Tweak README

Provide dedicated install-completion Makefile target instead.

.builds/alpine.yml

@@ -0,0 +1,11 @@
+image: alpine/edge
+sources:
+  - https://github.com/martanne/abduco
+tasks:
+  - build: |
+      cd abduco
+      ./configure
+      make
+  - test: |
+      cd abduco
+      ./testsuite.sh

.builds/debian.yml

@@ -0,0 +1,11 @@
+image: debian/stable
+sources:
+  - https://github.com/martanne/abduco
+tasks:
+  - build: |
+      cd abduco
+      ./configure
+      make
+  - test: |
+      cd abduco
+      ./testsuite.sh

.builds/freebsd.yml

@@ -0,0 +1,11 @@
+image: freebsd/latest
+sources:
+  - https://github.com/martanne/abduco
+tasks:
+  - build: |
+      cd abduco
+      ./configure
+      make
+  - test: |
+      cd abduco
+      ./testsuite.sh

.builds/openbsd.yml

@@ -0,0 +1,11 @@
+image: openbsd/latest
+sources:
+  - https://github.com/martanne/abduco
+tasks:
+  - build: |
+      cd abduco
+      ./configure
+      make
+  - test: |
+      cd abduco
+      ./testsuite.sh

.github/workflows/coverity-scan.yml

@@ -0,0 +1,46 @@
+name: Coverity Scan
+
+env:
+  PROJECT: abduco
+
+on:
+  schedule:
+    - cron: '0 0 * * 0' # once a week
+
+jobs:
+  scan:
+    runs-on: ubuntu-latest
+    steps:
+
+    - name: Checkout
+      uses: actions/checkout@v2
+
+    - name: Download Coverity Build Tool
+      run: |
+        wget -q https://scan.coverity.com/download/cxx/linux64 --post-data "token=$TOKEN&project=martanne/${PROJECT}" -O cov-analysis-linux64.tar.gz
+        mkdir cov-analysis-linux64
+        tar xzf cov-analysis-linux64.tar.gz --strip 1 -C cov-analysis-linux64
+      env:
+        TOKEN: ${{ secrets.COVERITY_SCAN_TOKEN }}
+
+    - name: Configure
+      run: ./configure
+
+    - name: Build with cov-build
+      run: |
+        export PATH=$(pwd)/cov-analysis-linux64/bin:$PATH
+        cov-build --dir cov-int make
+
+    - name: Submit the result to Coverity Scan
+      run: |
+        tar czvf ${PROJECT}.tgz cov-int
+        curl \
+          --form project=martanne/${PROJECT} \
+          --form token=$TOKEN \
+          --form email=mat@brain-dump.org \
+          --form file=@${PROJECT}.tgz \
+          --form version=trunk \
+          --form description="`./${PROJECT} -v`" \
+          https://scan.coverity.com/builds?project=martanne/${PROJECT}
+      env:
+        TOKEN: ${{ secrets.COVERITY_SCAN_TOKEN }}

.github/workflows/macos.yml

@@ -0,0 +1,24 @@
+name: macOS
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    strategy:
+      matrix:
+        os:
+          - macos-10.15
+    runs-on: ${{ matrix.os }}
+    steps:
+
+    - name: Checkout
+      uses: actions/checkout@v2
+
+    - name: Build
+      run: |
+        ./configure
+        make
+
+    - name: Test
+      run: |
+        ./testsuite.sh

.github/workflows/man.yml

@@ -0,0 +1,44 @@
+name: Manual
+
+env:
+  PROJECT: abduco
+
+on:
+  push:
+    paths:
+    - '*.1'
+
+jobs:
+  man:
+    runs-on: ubuntu-latest
+    steps:
+
+    - name: Checkout
+      uses: actions/checkout@v2
+
+    - name: Dependency
+      run: sudo apt install mandoc
+
+    - name: Manual generation
+      run: |
+        mkdir man
+        sed -e "s/VERSION/$(git describe --always)/" ${PROJECT}.1 | \
+          mandoc -W warning -T utf8 -T html -O man=%N.%S.html -O style=mandoc.css 1> \
+          "man/${PROJECT}.1.html" || true
+        wget 'https://cvsweb.bsd.lv/~checkout~/mandoc/mandoc.css?rev=1.46&content-type=text/plain' -O man/mandoc.css
+        ln -sf "${PROJECT}.1.html" man/index.html
+
+    - name: Upload
+      env:
+        DEPLOY_TOKEN: ${{ secrets.GIT_DEPLOY_TOKEN }}
+      run: |
+        git clone --depth=1 --single-branch --branch gh-pages "https://x-access-token:${DEPLOY_TOKEN}@github.com/${GITHUB_REPOSITORY}.git" /tmp/gh-pages
+        git config --global user.name "${GITHUB_ACTOR}"
+        git config --global user.email "${GITHUB_ACTOR}@users.noreply.github.com"
+        mkdir -p /tmp/gh-pages/man
+        rm -f /tmp/gh-pages/man/*
+        cp -av man/*.html /tmp/gh-pages/man/
+        cp -av man/*.css /tmp/gh-pages/man/
+        cd /tmp/gh-pages
+        git add -A && git commit --allow-empty -am "Publishing from ${GITHUB_REPOSITORY} ${GITHUB_SHA}"
+        git push origin gh-pages

.gitignore

@@ -1,7 +1,9 @@
-# normal ignores
-.*
-*.[ao]
-*.lo
-*.so
-tags
-!.gitignore
+/config.h
+/config.mk
+/abduco
+*.css
+*.gcda
+*.gcno
+*.gcov
+*.html
+*.o

.travis.yml

@@ -1,8 +0,0 @@
-language: c
-compiler:
-  - gcc
-  - clang
-env:
-  - DEBUG=
-  - DEBUG=debug
-script: make $DEBUG

LICENSE

@@ -1,4 +1,6 @@
-Copyright (c) 2013-2015 Marc André Tanner <mat at brain-dump.org>
+ISC License
+
+Copyright (c) 2013-2018 Marc André Tanner <mat at brain-dump.org>
 
 Permission to use, copy, modify, and/or distribute this software for any
 purpose with or without fee is hereby granted, provided that the above

Makefile

@@ -1,62 +1,67 @@
-include config.mk
+-include config.mk
+
+VERSION = 0.6
+
+CFLAGS_STD ?= -std=c99 -D_POSIX_C_SOURCE=200809L -D_XOPEN_SOURCE=700 -DNDEBUG
+CFLAGS_STD += -DVERSION=\"${VERSION}\"
+
+LDFLAGS_STD ?= -lc -lutil
+
+STRIP ?= strip
+INSTALL ?= install
+
+PREFIX ?= /usr/local
+SHAREDIR ?= ${PREFIX}/share
 
 SRC = abduco.c
-OBJ = ${SRC:.c=.o}
 
-all: clean options abduco
-
-options:
-	@echo abduco build options:
-	@echo "CFLAGS   = ${CFLAGS}"
-	@echo "LDFLAGS  = ${LDFLAGS}"
-	@echo "CC       = ${CC}"
+all: abduco
 
 config.h:
 	cp config.def.h config.h
 
-.c.o:
-	@echo CC $<
-	@${CC} -c ${CFLAGS} $<
+config.mk:
+	@touch $@
 
-${OBJ}: config.h config.mk
-
-abduco: ${OBJ}
-	@echo CC -o $@
-	@${CC} -o $@ ${OBJ} ${LDFLAGS}
+abduco: config.h config.mk *.c
+	${CC} ${CFLAGS} ${CFLAGS_STD} ${CFLAGS_AUTO} ${CFLAGS_EXTRA} ${SRC} ${LDFLAGS} ${LDFLAGS_STD} ${LDFLAGS_AUTO} -o $@
 
 debug: clean
-	@make CFLAGS='${DEBUG_CFLAGS}'
+	make CFLAGS_EXTRA='${CFLAGS_DEBUG}'
 
 clean:
 	@echo cleaning
-	@rm -f abduco ${OBJ} abduco-${VERSION}.tar.gz
+	@rm -f abduco abduco-*.tar.gz
 
 dist: clean
 	@echo creating dist tarball
-	@mkdir -p abduco-${VERSION}
-	@cp -R LICENSE Makefile README.md testsuite.sh config.def.h config.mk \
-		${SRC} debug.c client.c server.c forkpty-aix.c forkpty-sunos.c \
-		abduco.1 abduco-${VERSION}
-	@tar -cf abduco-${VERSION}.tar abduco-${VERSION}
-	@gzip abduco-${VERSION}.tar
-	@rm -rf abduco-${VERSION}
+	@git archive --prefix=abduco-${VERSION}/ -o abduco-${VERSION}.tar.gz HEAD
 
-install: abduco
-	@echo stripping executable
-	@${STRIP} abduco
+installdirs:
+	@${INSTALL} -d ${DESTDIR}${PREFIX}/bin \
+		${DESTDIR}${MANPREFIX}/man1
+
+install: abduco installdirs
 	@echo installing executable file to ${DESTDIR}${PREFIX}/bin
-	@mkdir -p ${DESTDIR}${PREFIX}/bin
-	@cp -f abduco ${DESTDIR}${PREFIX}/bin
-	@chmod 755 ${DESTDIR}${PREFIX}/bin/abduco
+	@${INSTALL} -m 0755 abduco ${DESTDIR}${PREFIX}/bin
 	@echo installing manual page to ${DESTDIR}${MANPREFIX}/man1
 	@mkdir -p ${DESTDIR}${MANPREFIX}/man1
 	@sed "s/VERSION/${VERSION}/g" < abduco.1 > ${DESTDIR}${MANPREFIX}/man1/abduco.1
 	@chmod 644 ${DESTDIR}${MANPREFIX}/man1/abduco.1
 
+install-strip: install
+	${STRIP} ${DESTDIR}${PREFIX}/bin/abduco
+
+install-completion:
+	@echo installing zsh completion file to ${DESTDIR}${SHAREDIR}/zsh/site-functions
+	@install -Dm644 contrib/abduco.zsh ${DESTDIR}${SHAREDIR}/zsh/site-functions/_abduco
+
 uninstall:
 	@echo removing executable file from ${DESTDIR}${PREFIX}/bin
 	@rm -f ${DESTDIR}${PREFIX}/bin/abduco
 	@echo removing manual page from ${DESTDIR}${MANPREFIX}/man1
 	@rm -f ${DESTDIR}${MANPREFIX}/man1/abduco.1
+	@echo removing zsh completion file from ${DESTDIR}${SHAREDIR}/zsh/site-functions
+	@rm -f ${DESTDIR}${SHAREDIR}/zsh/site-functions/_abduco
 
-.PHONY: all options clean dist install uninstall debug
+.PHONY: all clean dist install installdirs install-strip install-completion uninstall debug

README.md

@@ -1,15 +1,15 @@
 # abduco a tool for session {at,de}tach support
 
-[abduco](http://www.brain-dump.org/projects/abduco) provides
+[abduco](https://www.brain-dump.org/projects/abduco) provides
 session management i.e. it allows programs to be run independently
 from their controlling terminal. That is programs can be detached -
 run in the background - and then later reattached. Together with
-[dvtm](http://www.brain-dump.org/projects/dvtm) it provides a
+[dvtm](https://www.brain-dump.org/projects/dvtm) it provides a
 simpler and cleaner alternative to tmux or screen.
 
-![abduco+dvtm demo](https://raw.githubusercontent.com/martanne/abduco/gh-pages/screencast.gif)
+![abduco+dvtm demo](https://raw.githubusercontent.com/martanne/abduco/gh-pages/screencast.gif#center)
 
-abduco is in many ways very similar to [dtach]("http://dtach.sf.net)
+abduco is in many ways very similar to [dtach](http://dtach.sf.net)
 but is a completely independent implementation which is actively maintained,
 contains no legacy code, provides a few additional features, has a
 cleaner, more robust implementation and is distributed under the
@@ -17,34 +17,30 @@ cleaner, more robust implementation and is distributed under the
 
 ## News
 
- * [abduco-0.3](http://www.brain-dump.org/projects/abduco/abduco-0.3.tar.gz)
-   [released](http://lists.suckless.org/dev/1502/25557.html) (19.02.2015)
- * [abduco-0.2](http://www.brain-dump.org/projects/abduco/abduco-0.2.tar.gz)
-   [released](http://lists.suckless.org/dev/1411/24447.html) (15.11.2014)
- * [abduco-0.1](http://www.brain-dump.org/projects/abduco/abduco-0.1.tar.gz)
-   [released](http://lists.suckless.org/dev/1407/22703.html) (05.07.2014)
- * [Initial announcement](http://lists.suckless.org/dev/1403/20372.html)
+ * [abduco-0.6](https://www.brain-dump.org/projects/abduco/abduco-0.6.tar.gz)
+   [released](https://lists.suckless.org/dev/1603/28589.html) (24.03.2016)
+ * [abduco-0.5](https://www.brain-dump.org/projects/abduco/abduco-0.5.tar.gz)
+   [released](https://lists.suckless.org/dev/1601/28094.html) (09.01.2016)
+ * [abduco-0.4](https://www.brain-dump.org/projects/abduco/abduco-0.4.tar.gz)
+   [released](https://lists.suckless.org/dev/1503/26027.html) (18.03.2015)
+ * [abduco-0.3](https://www.brain-dump.org/projects/abduco/abduco-0.3.tar.gz)
+   [released](https://lists.suckless.org/dev/1502/25557.html) (19.02.2015)
+ * [abduco-0.2](https://www.brain-dump.org/projects/abduco/abduco-0.2.tar.gz)
+   [released](https://lists.suckless.org/dev/1411/24447.html) (15.11.2014)
+ * [abduco-0.1](https://www.brain-dump.org/projects/abduco/abduco-0.1.tar.gz)
+   [released](https://lists.suckless.org/dev/1407/22703.html) (05.07.2014)
+ * [Initial announcement](https://lists.suckless.org/dev/1403/20372.html)
    on the suckless development mailing list (08.03.2014)
 
 ## Download
 
-Either download the latest source tarball
-[abduco-0.3.tar.gz](http://www.brain-dump.org/projects/abduco/abduco-0.3.tar.gz)
-with sha1sum
-
-    175b2c0eaf2a8b7fb044f1454d018dac4ec31293  abduco-0.3.tar.gz
-
+Either download the latest [source tarball](https://github.com/martanne/abduco/releases),
 compile and install it
 
-    $EDITOR config.mk && make && sudo make install
+    ./configure && make && sudo make install
 
-or use one of the distribution provided binary packages:
-
- * [Debian](https://packages.debian.org/search?keywords=abduco)
- * [Fedora](https://admin.fedoraproject.org/pkgdb/package/abduco/)
- * [Gentoo](http://packages.gentoo.org/package/app-misc/abduco/)
- * [Ubuntu](http://packages.ubuntu.com/search?keywords=abduco)
- * [Mac OS X](http://www.braumeister.org/formula/abduco) via homebrew
+or use one of the distribution provided
+[binary packages](https://repology.org/project/abduco/packages).
 
 ## Quickstart
 
@@ -52,7 +48,7 @@ In order to create a new session `abduco` requires a session name
 as well as an command which will be run. If no command is given
 the environment variable `$ABDUCO_CMD` is examined and if not set
 `dvtm` is executed. Therefore assuming `dvtm` is located somewhere
-in `$PATH` a new session named *demo* is created with: 
+in `$PATH` a new session named *demo* is created with:
 
     $ abduco -c demo
 
@@ -61,7 +57,7 @@ An arbitrary application can be started as follows:
     $ abduco -c session-name your-application
 
 `CTRL-\` detaches from the active session. This detach key can be
-changed by means of the `-e` command line option, `-e ^q` would 
+changed by means of the `-e` command line option, `-e ^q` would
 for example set it to `CTRL-q`.
 
 To get an overview of existing session run `abduco` without any
@@ -81,7 +77,13 @@ A session can be reattached by using the `-a` command line option
 in combination with the session name which was used during session
 creation.
 
-    abduco -a demo
+    $ abduco -a demo
+
+If you encounter problems with incomplete redraws or other
+incompatibilities it is recommended to run your applications
+within [dvtm](https://github.com/martanne/dvtm) under abduco:
+
+    $ abduco -c demo dvtm your-application
 
 Check out the manual page for further information and all available
 command line options.
@@ -103,11 +105,36 @@ command line options.
    attaching to a session, then all keyboard input is ignored and the
    client is a passive observer only.
 
+   Note that this is not a security feature, but only a convenient way to
+   avoid accidental keyboard input.
+
+   If you want to make your abduco session available to another user
+   in a read only fashion, use [socat](http://www.dest-unreach.org/socat/)
+   to proxy the abduco socket in a unidirectional (from the abduco server
+   to the client, but not vice versa) way.
+
+   Start your to be shared session, make sure only you have access to
+   the `private` directory:
+
+        $ abduco -c /tmp/abduco/private/session
+
+   Then proxy the socket in unidirectional mode `-u` to a directory
+   where the desired observers have sufficient access rights:
+
+        $ socat -u unix-connect:/tmp/abduco/private/session unix-listen:/tmp/abduco/public/read-only &
+
+   Now the observers can connect to the read-only side of the socket:
+
+        $ abduco -a /tmp/abduco/public/read-only
+
+   communication in the other direction will not be possible and keyboard
+   input will hence be discarded.
+
  * **better resize handling** on shared sessions, resize request are only
-   processed if they are initiated by the most recently connected, non 
+   processed if they are initiated by the most recently connected, non
    read only client.
 
- * **socket recreation** by sending the `SIGUSR1` signal to the server 
+ * **socket recreation** by sending the `SIGUSR1` signal to the server
    process. In case the unix domain socket was removed by accident it
    can be recreated. The simplest way to find out the server process
    id is to look for abduco processes which are reparented to the init
@@ -119,7 +146,7 @@ command line options.
 
         $ kill -USR1 $PID
 
-   If the abduco binary itself has also been deleted, but a session is 
+   If the abduco binary itself has also been deleted, but a session is
    still running, use the following command to bring back the session:
 
         $ /proc/$PID/exe
@@ -130,21 +157,28 @@ command line options.
 
 ## Development
 
-You can always fetch the current code base from the git repository.
-
-    git clone https://github.com/martanne/abduco.git
-
-or
-
-    git clone git://repo.or.cz/abduco.git
+You can always fetch the current code base from the git repository
+located at [Github](https://github.com/martanne/abduco/) or
+[Sourcehut](https://git.sr.ht/~martanne/abduco).
 
 If you have comments, suggestions, ideas, a bug report, a patch or something
-else related to abduco then write to the 
-[suckless developer mailing list](http://suckless.org/community) 
-or contact me directly mat[at]brain-dump.org.
+else related to abduco then write to the
+[suckless developer mailing list](https://suckless.org/community)
+or contact me directly.
 
-[![Build Status](https://travis-ci.org/martanne/abduco.svg?branch=master)](https://travis-ci.org/martanne/abduco)
-[![Coverity Scan Build Status](https://scan.coverity.com/projects/4285/badge.svg)](https://scan.coverity.com/projects/4285)
+### Debugging
+
+The protocol content exchanged between client and server can be dumped
+to temporary files as follows:
+
+    $ make debug
+    $ ./abduco -n debug [command-to-debug] 2> server-log
+    $ ./abduco -a debug 2> client-log
+
+If you want to run client and server with one command (e.g. using the `-c`
+option) then within `gdb` the option `set follow-fork-mode {child,parent}`
+might be useful. Similarly to get a syscall trace `strace -o abduco -ff
+[abduco-cmd]` proved to be handy.
 
 ## License
 

abduco.1

@@ -1,128 +1,226 @@
-.TH ABDUCO 1 abduco\-VERSION
-.nh
-.SH NAME
-abduco - terminal session manager
-.SH SYNOPSIS
-.B abduco
-.RB [ \-e
-.IR detachkey ]
-.RB [ \-r ]
-.RB [ \-f ]
-.RB \-c
-.RB name
-.RB command
-.RI [ args \ ... "" ]
-.br
-.B abduco
-.RB [ \-e
-.IR detachkey ]
-.RB [ \-r ]
-.RB [ \-f ]
-.RB \-n
-.RB name
-.RB command
-.RI [ args \ ... "" ]
-.br
-.B abduco
-.RB [ \-e
-.IR detachkey ]
-.RB [ \-r ]
-.RB [ \-f ]
-.RB \-A
-.RB name
-.RB command
-.RI [ args \ ... "" ]
-.br
-.B abduco
-.RB [ \-e
-.IR detachkey ]
-.RB [ \-r ]
-.RB \-a
-.RB name
-.br
-.SH DESCRIPTION
-.B abduco
-provides a way to disconnect a given application from its controlling
-terminal, thus it provides roughly the same session attach/detach support as
-.BR screen(1) , " tmux(1)" " or" " dtach(1)".
-
-If the
-.BR command
-to execute is not specified, the environment variable
-.BR $ABDUCO_CMD
-is examined, if it is not set
-.BR dvtm(1)
-is executed.
-
-By default all session related information is stored in
-.B $HOME/.abduco
-with
-.BR $TMPDIR/abduco/$USER
-as a fallback and
-.BR /tmp/abduco/$USER
-as a last resort.
-
-However if a given session name represents either a relative or absolute path
-it is used unmodified.
-
-If for some reason the
-.BR unix(7)
-domain socket representing a session is deleted, sending
-.BR SIGUSR1
-to the server process will recreate it.
-.SH OPTIONS
-If no command line arguments are given all currently active sessions are
-printed sorted by their respective creation date. Lines starting with an
-asterik
-.BR *
-indicate that at least one client is connected.
+.Dd March 18, 2018
+.Dt ABDUCO 1
+.Os abduco VERSION
+.
+.Sh NAME
+.Nm abduco
+.Nd terminal session manager
+.
+.Sh SYNOPSIS
+.Nm
+.Fl a
+.Op options ...
+.Cm name
+.
+.Nm
+.Fl A
+.Op options ...
+.Cm name
+.Cm command Op args ...
+.
+.Nm
+.Fl c
+.Op options ...
+.Cm name
+.Cm command Op args ...
+.
+.Nm
+.Fl n
+.Op options ...
+.Cm name
+.Cm command Op args ...
+.
+.Sh DESCRIPTION
+.
+.Nm
+disassociates a given application from its controlling
+terminal, thereby providing roughly the same session attach/detach support as
+.Xr screen 1 ,
+.Xr tmux 1 ,
+or
+.Xr dtach 1 .
+.Pp
+A session comprises of an
+.Nm
+server process which spawns a user
+command in its own pseudo terminal
+.Pq see Xr pty 7 .
+Each session is given a name represented by a unix domain socket
+.Pq see Xr unix 7
+stored in the local file system.
+.Nm
+clients can connect to it and their standard input output streams
+are relayed to the command supervised by the server.
+.Pp
+.Nm
+operates on the raw I/O byte stream without interpreting any terminal
+escape sequences.
+As a consequence the terminal state is not preserved across sessions.
+If this functionality is desired, it should be provided by another
+utility such as
+.Xr dvtm 1 .
+.
+.Ss ACTIONS
+.
+If no command line arguments are given, all currently active sessions are
+listed sorted by their respective creation date.
+Lines starting with an asterisk
+.Pq *
+indicate that at least one client is currently connected.
 A plus sign
-.BR +
-indicates that the command terminated while no client was connected, attach
-to get its exit status.
-.TP
-.B \-v
-Print version information to standard output and exit.
-.TP
-.B \-r
-Readonly session, i.e. user input is ignored.
-.TP
-.BI \-e \ detachkey
-Set the key to detach which by default is set to CTRL+\\ i.e. ^\\ to detachkey.
-.TP
-.BI \-f
+.Pq +
+signals that the command terminated while no client was connected.
+Attaching to the session will print its exit status.
+The next column shows the PID of the server process, followed by the session
+.Ic name .
+.Pp
+.Nm
+provides different actions of which one must be provided.
+.
+.Bl -tag -width indent
+.It Fl a
+Attach to an existing session.
+.It Fl A
+Try to connect to an existing session, upon failure create said session and attach immediately to it.
+.It Fl c
+Create a new session and attach immediately to it.
+.It Fl n
+Create a new session but do not attach to it.
+.El
+.
+.Ss OPTIONS
+.
+Additionally the following options can be provided to further tweak
+the behavior.
+.Bl -tag -width indent
+.It Fl e Ar detachkey
+Set the key to detach.
+Defaults to
+.Aq Ctrl+\e
+which is specified as ^\\ i.e. Ctrl is represented as a caret
+.Pq ^ .
+.It Fl f
 Force creation of session when there is an already terminated session of the same name,
 after showing its exit status.
-.TP
-.BI \-c
-Create a new session and attach immediately to it.
-.TP
-.BI \-n
-Create a new session but do not attach to it.
-.TP
-.BI \-A
-Try to connect to an existing session, upon failure create said session and attach immediately to it.
-.TP
-.BI \-a
-Attach to an existing session.
-.SH EXAMPLE
+.It Fl l
+Attach with the lowest priority, meaning this client will be the last to control the size.
+.It Fl p
+Pass through content of standard input to the session.
+Implies the
+.Fl q
+and
+.Fl l
+options.
+.It Fl q
+Be quiet, do not print informative messages.
+.It Fl r
+Read-only session, user input is ignored.
+.It Fl v
+Print version information and exit.
+.El
+.
+.Sh SIGNALS
+.
+.Bl -tag -width indent
+.It Dv SIGWINCH
+Whenever the primary client resizes its terminal the server process will deliver a
+.Ev SIGWINCH
+signal to the supervised process.
+.It Dv SIGUSR1
+If for some reason the unix domain socket representing a session is deleted, sending
+.Ev SIGUSR1
+to the server process will recreate it.
+.It Dv SIGTERM
+Detaches a client.
+.El
+.
+.Sh ENVIRONMENT
+.
+.Bl -tag -width indent
+.It Ev ABDUCO_CMD
+If
+.Ic command
+is not specified, the environment variable
+.Ev $ABDUCO_CMD
+is examined, if it is not set
+.Xr dvtm 1
+is executed.
+.It Ev ABDUCO_SESSION
+The current session name available to the supervised command.
+.It Ev ABDUCO_SOCKET
+The absolute path of the session socket available to the supervised command.
+.El
+.Pp
+See the
+.Sx FILES
+section for environment variables used in determining the location
+of unix domain sockets representing sessions.
+.Sh FILES
+.
+All session related information is stored in the following directories (first
+to succeed is used):
+.Bl -bullet
+.It
+.Ev $ABDUCO_SOCKET_DIR/abduco
+.It
+.Ev $HOME/.abduco
+.It
+.Ev $TMPDIR/abduco/$USER
+.It
+.Ev /tmp/abduco/$USER
+.El
+.
+.Pp
+However, if a given session
+.Ic name
+represents either a relative or absolute path it is used unmodified.
+.
+.
+.Sh EXAMPLES
+.
 Start a new session (assuming
-.BR dvtm(1)
+.Xr dvtm 1
 is in
-.BR $PATH )
+.Ev $PATH )
 with
-.nf
-
-.B abduco -c my-session
-
-.fi
+.Pp
+.Dl $ abduco -c my-session
+.Pp
 do some work, then detach by pressing
-.B CTRL+\e
-and later reattach with
-.nf
-
-.B abduco -a my-session
-
-.fi
-.SH AUTHOR
-abduco is written by Marc André Tanner <mat at brain-dump.org>
+.Aq Ctrl+\e ,
+list existing session by running
+.Nm
+without any arguments and later reattach with
+.Pp
+.Dl $ abduco -a my-session
+.Pp
+Alternatively, we can also explicitly specify the command to run.
+.Pp
+.Dl $ abduco -c my-session /bin/sh
+.Pp
+Attach with a
+.Aq Ctrl+z
+as detach key.
+.Pp
+.Dl $ abduco -e ^z -a my-session
+.Pp
+Send a command to an existing session.
+.Pp
+.Dl $ echo make | abduco -a my-session
+.Pp
+Or in a slightly more interactive fashion.
+.Pp
+.Dl $ abduco -p my-session
+.Dl make
+.Dl ^D
+.
+.Sh SEE ALSO
+.Xr dvtm 1 ,
+.Xr dtach 1 ,
+.Xr tmux 1 ,
+.Xr screen 1
+.
+.Sh AUTHORS
+.Nm
+is written by
+.An Marc André Tanner Aq mat at brain-dump.org

abduco.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2015 Marc André Tanner <mat at brain-dump.org>
+ * Copyright (c) 2013-2018 Marc André Tanner <mat at brain-dump.org>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -15,6 +15,7 @@
  */
 #include <errno.h>
 #include <fcntl.h>
+#include <inttypes.h>
 #include <stdio.h>
 #include <stdarg.h>
 #include <stdlib.h>
@@ -66,18 +67,21 @@ enum PacketType {
 	MSG_ATTACH  = 1,
 	MSG_DETACH  = 2,
 	MSG_RESIZE  = 3,
-	MSG_REDRAW  = 4,
-	MSG_EXIT    = 5,
+	MSG_EXIT    = 4,
+	MSG_PID     = 5,
 };
 
 typedef struct {
-	unsigned int type;
-	size_t len;
+	uint32_t type;
+	uint32_t len;
 	union {
-		char msg[BUFSIZ];
-		struct winsize ws;
-		int i;
-		bool b;
+		char msg[4096 - 2*sizeof(uint32_t)];
+		struct {
+			uint16_t rows;
+			uint16_t cols;
+		} ws;
+		uint32_t i;
+		uint64_t l;
 	} u;
 } Packet;
 
@@ -91,7 +95,10 @@ struct Client {
 		STATE_DISCONNECTED,
 	} state;
 	bool need_resize;
-	bool readonly;
+	enum {
+		CLIENT_READONLY = 1 << 0,
+		CLIENT_LOWPRIORITY = 1 << 1,
+	} flags;
 	Client *next;
 };
 
@@ -114,7 +121,7 @@ typedef struct {
 static Server server = { .running = true, .exit_status = -1, .host = "@localhost" };
 static Client client;
 static struct termios orig_term, cur_term;
-static bool has_term, alternate_buffer;
+static bool has_term, alternate_buffer, quiet, passthrough;
 
 static struct sockaddr_un sockaddr = {
 	.sun_family = AF_UNIX,
@@ -201,12 +208,12 @@ static bool recv_packet(int socket, Packet *pkt) {
 static void info(const char *str, ...) {
 	va_list ap;
 	va_start(ap, str);
-	if (str) {
+	if (str && !quiet) {
 		fprintf(stderr, "%s: %s: ", server.name, server.session_name);
 		vfprintf(stderr, str, ap);
 		fprintf(stderr, "\r\n");
+		fflush(stderr);
 	}
-	fflush(stderr);
 	va_end(ap);
 }
 
@@ -216,7 +223,7 @@ static void die(const char *s) {
 }
 
 static void usage(void) {
-	fprintf(stderr, "usage: abduco [-a|-A|-c|-n] [-r] [-f] [-e detachkey] name command\n");
+	fprintf(stderr, "usage: abduco [-a|-A|-c|-n] [-p] [-r] [-q] [-l] [-f] [-e detachkey] name command\n");
 	exit(EXIT_FAILURE);
 }
 
@@ -236,28 +243,65 @@ static bool xsnprintf(char *buf, size_t size, const char *fmt, ...) {
 	return true;
 }
 
+static int session_connect(const char *name) {
+	int fd;
+	struct stat sb;
+	if (!set_socket_name(&sockaddr, name) || (fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1)
+		return -1;
+	socklen_t socklen = offsetof(struct sockaddr_un, sun_path) + strlen(sockaddr.sun_path) + 1;
+	if (connect(fd, (struct sockaddr*)&sockaddr, socklen) == -1) {
+		if (errno == ECONNREFUSED && stat(sockaddr.sun_path, &sb) == 0 && S_ISSOCK(sb.st_mode))
+			unlink(sockaddr.sun_path);
+		close(fd);
+		return -1;
+	}
+	return fd;
+}
+
+static pid_t session_exists(const char *name) {
+	Packet pkt;
+	pid_t pid = 0;
+	if ((server.socket = session_connect(name)) == -1)
+		return pid;
+	if (client_recv_packet(&pkt) && pkt.type == MSG_PID)
+		pid = pkt.u.l;
+	close(server.socket);
+	return pid;
+}
+
+static bool session_alive(const char *name) {
+	struct stat sb;
+	return session_exists(name) &&
+	       stat(sockaddr.sun_path, &sb) == 0 &&
+	       S_ISSOCK(sb.st_mode) && (sb.st_mode & S_IXGRP) == 0;
+}
+
 static bool create_socket_dir(struct sockaddr_un *sockaddr) {
 	sockaddr->sun_path[0] = '\0';
-	uid_t uid = getuid();
-	size_t maxlen = sizeof(sockaddr->sun_path);
-	char *dirs[] = { getenv("HOME"), getenv("TMPDIR"), "/tmp" };
 	int socketfd = socket(AF_UNIX, SOCK_STREAM, 0);
 	if (socketfd == -1)
 		return false;
-	struct passwd *pw = getpwuid(uid);
-	if ((!dirs[0] || !dirs[0][0]) && pw)
-		dirs[0] = pw->pw_dir;
 
-	for (unsigned int i = 0; i < countof(dirs); i++) {
-		char *dir = dirs[i];
+	const size_t maxlen = sizeof(sockaddr->sun_path);
+	uid_t uid = getuid();
+	struct passwd *pw = getpwuid(uid);
+
+	for (unsigned int i = 0; i < countof(socket_dirs); i++) {
 		struct stat sb;
-		bool ishome = (i == 0);
-		if (!dir)
+		struct Dir *dir = &socket_dirs[i];
+		bool ishome = false;
+		if (dir->env) {
+			dir->path = getenv(dir->env);
+			ishome = !strcmp(dir->env, "HOME");
+			if (ishome && (!dir->path || !dir->path[0]) && pw)
+				dir->path = pw->pw_dir;
+		}
+		if (!dir->path || !dir->path[0])
 			continue;
-		if (!xsnprintf(sockaddr->sun_path, maxlen, "%s/%s%s/", dir, ishome ? "." : "", server.name))
+		if (!xsnprintf(sockaddr->sun_path, maxlen, "%s/%s%s/", dir->path, ishome ? "." : "", server.name))
 			continue;
 		mode_t mask = umask(0);
-		int r = mkdir(sockaddr->sun_path, ishome ? S_IRWXU : S_IRWXU|S_IRWXG|S_IRWXO|S_ISVTX);
+		int r = mkdir(sockaddr->sun_path, dir->personal ? S_IRWXU : S_IRWXU|S_IRWXG|S_IRWXO|S_ISVTX);
 		umask(mask);
 		if (r != 0 && errno != EEXIST)
 			continue;
@@ -269,7 +313,8 @@ static bool create_socket_dir(struct sockaddr_un *sockaddr) {
 		}
 
 		size_t dirlen = strlen(sockaddr->sun_path);
-		if (!ishome) {
+		if (!dir->personal) {
+			/* create subdirectory only accessible to user */
 			if (pw && !xsnprintf(sockaddr->sun_path+dirlen, maxlen-dirlen, "%s/", pw->pw_name))
 				continue;
 			if (!pw && !xsnprintf(sockaddr->sun_path+dirlen, maxlen-dirlen, "%d/", uid))
@@ -307,7 +352,10 @@ static bool create_socket_dir(struct sockaddr_un *sockaddr) {
 }
 
 static bool set_socket_name(struct sockaddr_un *sockaddr, const char *name) {
-	size_t maxlen = sizeof(sockaddr->sun_path);
+	const size_t maxlen = sizeof(sockaddr->sun_path);
+	const char *session_name = NULL;
+	char buf[maxlen];
+
 	if (name[0] == '/') {
 		if (strlen(name) >= maxlen) {
 			errno = ENAMETOOLONG;
@@ -315,7 +363,7 @@ static bool set_socket_name(struct sockaddr_un *sockaddr, const char *name) {
 		}
 		strncpy(sockaddr->sun_path, name, maxlen);
 	} else if (name[0] == '.' && (name[1] == '.' || name[1] == '/')) {
-		char buf[maxlen], *cwd = getcwd(buf, sizeof buf);
+		char *cwd = getcwd(buf, sizeof buf);
 		if (!cwd)
 			return false;
 		if (!xsnprintf(sockaddr->sun_path, maxlen, "%s/%s", cwd, name))
@@ -327,9 +375,18 @@ static bool set_socket_name(struct sockaddr_un *sockaddr, const char *name) {
 			errno = ENAMETOOLONG;
 			return false;
 		}
+		session_name = name;
 		strncat(sockaddr->sun_path, name, maxlen - strlen(sockaddr->sun_path) - 1);
 		strncat(sockaddr->sun_path, server.host, maxlen - strlen(sockaddr->sun_path) - 1);
 	}
+
+	if (!session_name) {
+		strncpy(buf, sockaddr->sun_path, sizeof buf);
+		session_name = basename(buf);
+	}
+	setenv("ABDUCO_SESSION", session_name, 1);
+	setenv("ABDUCO_SOCKET", sockaddr->sun_path, 1);
+
 	return true;
 }
 
@@ -340,7 +397,7 @@ static bool create_session(const char *name, char * const argv[]) {
 	 *
 	 * pipes are used for synchronization and error reporting i.e. the child sets
 	 * the close on exec flag before calling execvp(3) the parent blocks on a read(2)
-	 * in case of failure the error message is written to the pipe, success is 
+	 * in case of failure the error message is written to the pipe, success is
 	 * indicated by EOF on the pipe.
 	 */
 	int client_pipe[2], server_pipe[2];
@@ -348,6 +405,11 @@ static bool create_session(const char *name, char * const argv[]) {
 	char errormsg[255];
 	struct sigaction sa;
 
+	if (session_exists(name)) {
+		errno = EADDRINUSE;
+		return false;
+	}
+
 	if (pipe(client_pipe) == -1)
 		return false;
 	if ((server.socket = server_create_socket(name)) == -1)
@@ -401,13 +463,14 @@ static bool create_session(const char *name, char * const argv[]) {
 				sa.sa_handler = SIG_IGN;
 				sigaction(SIGPIPE, &sa, NULL);
 				sigaction(SIGHUP, &sa, NULL);
-				chdir("/");
+				if (chdir("/") == -1)
+					_exit(EXIT_FAILURE);
 			#ifdef NDEBUG
 				int fd = open("/dev/null", O_RDWR);
 				if (fd != -1) {
-					dup2(fd, 0);
-					dup2(fd, 1);
-					dup2(fd, 2);
+					dup2(fd, STDIN_FILENO);
+					dup2(fd, STDOUT_FILENO);
+					dup2(fd, STDERR_FILENO);
 					close(fd);
 				}
 			#endif /* NDEBUG */
@@ -438,8 +501,7 @@ static bool create_session(const char *name, char * const argv[]) {
 		return false;
 	default: /* parent = client process */
 		close(client_pipe[1]);
-		int status;
-		wait(&status); /* wait for first fork */
+		while (waitpid(pid, NULL, 0) == -1 && errno == EINTR);
 		ssize_t len = read_all(client_pipe[0], errormsg, sizeof(errormsg));
 		if (len > 0) {
 			write_all(STDERR_FILENO, errormsg, len);
@@ -454,10 +516,7 @@ static bool create_session(const char *name, char * const argv[]) {
 static bool attach_session(const char *name, const bool terminate) {
 	if (server.socket > 0)
 		close(server.socket);
-	if (!set_socket_name(&sockaddr, name) || (server.socket = socket(AF_UNIX, SOCK_STREAM, 0)) == -1)
-		return false;
-	socklen_t socklen = offsetof(struct sockaddr_un, sun_path) + strlen(sockaddr.sun_path) + 1;
-	if (connect(server.socket, (struct sockaddr*)&sockaddr, socklen) == -1)
+	if ((server.socket = session_connect(name)) == -1)
 		return false;
 	if (server_set_socket_non_blocking(server.socket) == -1)
 		return false;
@@ -486,21 +545,6 @@ static bool attach_session(const char *name, const bool terminate) {
 	return terminate;
 }
 
-static bool session_exists(const char *name) {
-	struct stat sb;
-	if (!set_socket_name(&sockaddr, name))
-		return false;
-	return stat(sockaddr.sun_path, &sb) == 0 && S_ISSOCK(sb.st_mode);
-}
-
-static bool session_alive(const char *name) {
-	struct stat sb;
-	if (!set_socket_name(&sockaddr, name))
-		return false;
-	return stat(sockaddr.sun_path, &sb) == 0 && S_ISSOCK(sb.st_mode) &&
-	       (sb.st_mode & S_IXGRP) == 0;
-}
-
 static int session_filter(const struct dirent *d) {
 	return strstr(d->d_name, server.host) != NULL;
 }
@@ -517,7 +561,8 @@ static int session_comparator(const struct dirent **a, const struct dirent **b)
 static int list_session(void) {
 	if (!create_socket_dir(&sockaddr))
 		return 1;
-	chdir(sockaddr.sun_path);
+	if (chdir(sockaddr.sun_path) == -1)
+		die("list-session");
 	struct dirent **namelist;
 	int n = scandir(sockaddr.sun_path, &namelist, session_filter, session_comparator);
 	if (n < 0)
@@ -526,16 +571,20 @@ static int list_session(void) {
 	while (n--) {
 		struct stat sb; char buf[255];
 		if (stat(namelist[n]->d_name, &sb) == 0 && S_ISSOCK(sb.st_mode)) {
-			strftime(buf, sizeof(buf), "%a%t %F %T", localtime(&sb.st_atime));
+			pid_t pid = 0;
+			strftime(buf, sizeof(buf), "%a%t %F %T", localtime(&sb.st_mtime));
 			char status = ' ';
+			char *local = strstr(namelist[n]->d_name, server.host);
+			if (local) {
+				*local = '\0'; /* truncate hostname if we are local */
+				if (!(pid = session_exists(namelist[n]->d_name)))
+					continue;
+			}
 			if (sb.st_mode & S_IXUSR)
 				status = '*';
 			else if (sb.st_mode & S_IXGRP)
 				status = '+';
-			char *name = strstr(namelist[n]->d_name, server.host);
-			if (name)
-				*name = '\0';
-			printf("%c %s\t%s\n", status, buf, namelist[n]->d_name);
+			printf("%c %s\t%jd\t%s\n", status, buf, (intmax_t)pid, namelist[n]->d_name);
 		}
 		free(namelist[n]);
 	}
@@ -544,63 +593,83 @@ static int list_session(void) {
 }
 
 int main(int argc, char *argv[]) {
+	int opt;
 	bool force = false;
 	char **cmd = NULL, action = '\0';
+
+	char *default_cmd[4] = { "/bin/sh", "-c", getenv("ABDUCO_CMD"), NULL };
+	if (!default_cmd[2]) {
+		default_cmd[0] = ABDUCO_CMD;
+		default_cmd[1] = NULL;
+	}
+
 	server.name = basename(argv[0]);
 	gethostname(server.host+1, sizeof(server.host) - 1);
-	if (argc == 1)
-		exit(list_session());
-	for (int arg = 1; arg < argc; arg++) {
-		if (argv[arg][0] != '-') {
-			if (!server.session_name) {
-				server.session_name = argv[arg];
-				continue;
-			} else if (!cmd) {
-				cmd = &argv[arg];
-				break;
-			}
-		}
-		if (server.session_name)
-			usage();
-		switch (argv[arg][1]) {
+
+	while ((opt = getopt(argc, argv, "aAclne:fpqrv")) != -1) {
+		switch (opt) {
 		case 'a':
 		case 'A':
 		case 'c':
 		case 'n':
-			action = argv[arg][1];
+			action = opt;
 			break;
 		case 'e':
-			if (arg + 1 >= argc)
+			if (!optarg)
 				usage();
-			char *esc = argv[++arg];
-			if (esc[0] == '^' && esc[1])
-				*esc = CTRL(esc[1]);
-			KEY_DETACH = *esc;
+			if (optarg[0] == '^' && optarg[1])
+				optarg[0] = CTRL(optarg[1]);
+			KEY_DETACH = optarg[0];
 			break;
 		case 'f':
 			force = true;
 			break;
+		case 'p':
+			passthrough = true;
+			break;
+		case 'q':
+			quiet = true;
+			break;
 		case 'r':
-			client.readonly = true;
+			client.flags |= CLIENT_READONLY;
+			break;
+		case 'l':
+			client.flags |= CLIENT_LOWPRIORITY;
 			break;
 		case 'v':
-			puts("abduco-"VERSION" © 2013-2015 Marc André Tanner");
+			puts("abduco-"VERSION" © 2013-2018 Marc André Tanner");
 			exit(EXIT_SUCCESS);
 		default:
 			usage();
 		}
 	}
 
-	if (!cmd) {
-		cmd = (char*[]){ getenv("ABDUCO_CMD"), NULL };
-		if (!cmd[0])
-			cmd[0] = "dvtm";
+	/* collect the session name if trailing args */
+	if (optind < argc)
+		server.session_name = argv[optind];
+
+	/* if yet more trailing arguments, they must be the command */
+	if (optind + 1 < argc)
+		cmd = &argv[optind + 1];
+	else
+		cmd = default_cmd;
+
+	if (server.session_name && !isatty(STDIN_FILENO))
+		passthrough = true;
+
+	if (passthrough) {
+		if (!action)
+			action = 'a';
+		quiet = true;
+		client.flags |= CLIENT_LOWPRIORITY;
 	}
 
+	if (!action && !server.session_name)
+		exit(list_session());
 	if (!action || !server.session_name)
 		usage();
 
-	if (tcgetattr(STDIN_FILENO, &orig_term) != -1) {
+	if (!passthrough && tcgetattr(STDIN_FILENO, &orig_term) != -1) {
 		server.term = orig_term;
 		has_term = true;
 	}
@@ -628,14 +697,16 @@ int main(int argc, char *argv[]) {
 			die("create-session");
 		if (action == 'n')
 			break;
+		/* fall through */
 	case 'a':
 		if (!attach_session(server.session_name, true))
 			die("attach-session");
 		break;
 	case 'A':
-		if (session_alive(server.session_name) && !attach_session(server.session_name, true))
-			die("attach-session");
-		if (!attach_session(server.session_name, !force)) {
+		if (session_alive(server.session_name)) {
+			if (!attach_session(server.session_name, true))
+				die("attach-session");
+		} else if (!attach_session(server.session_name, !force)) {
 			force = false;
 			action = 'c';
 			goto redo;

client.c

@@ -22,16 +22,19 @@ static bool client_recv_packet(Packet *pkt) {
 }
 
 static void client_restore_terminal(void) {
-	if (has_term)
-		tcsetattr(STDIN_FILENO, TCSADRAIN, &orig_term);
+	if (!has_term)
+		return;
+	tcsetattr(STDIN_FILENO, TCSAFLUSH, &orig_term);
 	if (alternate_buffer) {
-		printf("\033[?1049l");
+		printf("\033[?25h\033[?1049l");
 		fflush(stdout);
 		alternate_buffer = false;
 	}
 }
 
 static void client_setup_terminal(void) {
+	if (!has_term)
+		return;
 	atexit(client_restore_terminal);
 
 	cur_term = orig_term;
@@ -43,7 +46,7 @@ static void client_setup_terminal(void) {
 	cur_term.c_cc[VLNEXT] = _POSIX_VDISABLE;
 	cur_term.c_cc[VMIN] = 1;
 	cur_term.c_cc[VTIME] = 0;
-	tcsetattr(STDIN_FILENO, TCSADRAIN, &cur_term);
+	tcsetattr(STDIN_FILENO, TCSANOW, &cur_term);
 
 	if (!alternate_buffer) {
 		printf("\033[?1049h\033[H");
@@ -62,8 +65,8 @@ static int client_mainloop(void) {
 	client.need_resize = true;
 	Packet pkt = {
 		.type = MSG_ATTACH,
-		.u = { .b = client.readonly },
-		.len = sizeof(pkt.u.b),
+		.u.i = client.flags,
+		.len = sizeof(pkt.u.i),
 	};
 	client_send_packet(&pkt);
 
@@ -78,8 +81,8 @@ static int client_mainloop(void) {
 			if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) != -1) {
 				Packet pkt = {
 					.type = MSG_RESIZE,
-					.u = { .ws = ws },
-					.len = sizeof(ws),
+					.u = { .ws = { .rows = ws.ws_row, .cols = ws.ws_col } },
+					.len = sizeof(pkt.u.ws),
 				};
 				if (client_send_packet(&pkt))
 					client.need_resize = false;
@@ -97,7 +100,8 @@ static int client_mainloop(void) {
 			if (client_recv_packet(&pkt)) {
 				switch (pkt.type) {
 				case MSG_CONTENT:
-					write_all(STDOUT_FILENO, pkt.u.msg, pkt.len);
+					if (!passthrough)
+						write_all(STDOUT_FILENO, pkt.u.msg, pkt.len);
 					break;
 				case MSG_RESIZE:
 					client.need_resize = true;
@@ -118,7 +122,7 @@ static int client_mainloop(void) {
 			if (len > 0) {
 				debug("client-stdin: %c\n", pkt.u.msg[0]);
 				pkt.len = len;
-				if (pkt.u.msg[0] == KEY_REDRAW) {
+				if (KEY_REDRAW && pkt.u.msg[0] == KEY_REDRAW) {
 					client.need_resize = true;
 				} else if (pkt.u.msg[0] == KEY_DETACH) {
 					pkt.type = MSG_DETACH;
@@ -126,9 +130,12 @@ static int client_mainloop(void) {
 					client_send_packet(&pkt);
 					close(server.socket);
 					return -1;
-				} else if (!client.readonly) {
+				} else if (!(client.flags & CLIENT_READONLY)) {
 					client_send_packet(&pkt);
 				}
+			} else if (len == 0) {
+				debug("client-stdin: EOF\n");
+				return -1;
 			}
 		}
 	}

config.def.h

@@ -1,2 +1,19 @@
+/* default command to execute if non is given and $ABDUCO_CMD is unset */
+#define ABDUCO_CMD "dvtm"
+/* default detach key, can be overriden at run time using -e option */
 static char KEY_DETACH = CTRL('\\');
+/* redraw key to send a SIGWINCH signal to underlying process
+ * (set to 0 to disable the redraw key) */
 static char KEY_REDRAW = 0;
+/* Where to place the "abduco" directory storing all session socket files.
+ * The first directory to succeed is used. */
+static struct Dir {
+	char *path;    /* fixed (absolute) path to a directory */
+	char *env;     /* environment variable to use if (set) */
+	bool personal; /* if false a user owned sub directory will be created */
+} socket_dirs[] = {
+	{ .env  = "ABDUCO_SOCKET_DIR", false },
+	{ .env  = "HOME",              true  },
+	{ .env  = "TMPDIR",            false },
+	{ .path = "/tmp",              false },
+};

config.mk

@@ -1,19 +0,0 @@
-# abduco version
-VERSION = 0.4
-
-# Customize below to fit your system
-
-PREFIX ?= /usr/local
-MANPREFIX = ${PREFIX}/share/man
-
-INCS = -I.
-LIBS = -lc -lutil
-
-CPPFLAGS = -D_POSIX_C_SOURCE=200809L -D_XOPEN_SOURCE=700
-CFLAGS += -std=c99 -pedantic -Wall ${INCS} -DVERSION=\"${VERSION}\" -DNDEBUG ${CPPFLAGS}
-LDFLAGS += ${LIBS}
-
-DEBUG_CFLAGS = ${CFLAGS} -UNDEBUG -O0 -g -ggdb
-
-CC ?= cc
-STRIP ?= strip

configure

@@ -0,0 +1,244 @@
+#!/bin/sh
+# Based on the configure script from musl libc, MIT licensed
+
+usage () {
+cat <<EOF
+Usage: $0 [OPTION]... [VAR=VALUE]...
+
+To assign environment variables (e.g., CC, CFLAGS...), specify them as
+VAR=VALUE.  See below for descriptions of some of the useful variables.
+
+Defaults for the options are specified in brackets.
+
+Configuration:
+  --srcdir=DIR            source directory [detected]
+
+Installation directories:
+  --prefix=PREFIX         main installation prefix [/usr/local]
+  --exec-prefix=EPREFIX   installation prefix for executable files [PREFIX]
+
+Fine tuning of the installation directories:
+  --bindir=DIR            user executables [EPREFIX/bin]
+  --sharedir=DIR          share directories [PREFIX/share]
+  --docdir=DIR            misc. documentation [PREFIX/share/doc]
+  --mandir=DIR            man pages [PREFIX/share/man]
+
+Some influential environment variables:
+  CC                      C compiler command [detected]
+  CFLAGS                  C compiler flags [-Os -pipe ...]
+  LDFLAGS                 Linker flags
+
+Use these variables to override the choices made by configure.
+
+EOF
+exit 0
+}
+
+# Helper functions
+
+quote () {
+tr '\n' ' ' <<EOF | grep '^[-[:alnum:]_=,./:]* $' >/dev/null 2>&1 && { echo "$1" ; return 0 ; }
+$1
+EOF
+printf %s\\n "$1" | sed -e "s/'/'\\\\''/g" -e "1s/^/'/" -e "\$s/\$/'/" -e "s#^'\([-[:alnum:]_,./:]*\)=\(.*\)\$#\1='\2#"
+}
+echo () { printf "%s\n" "$*" ; }
+fail () { echo "$*" ; exit 1 ; }
+fnmatch () { eval "case \"\$2\" in $1) return 0 ;; *) return 1 ;; esac" ; }
+cmdexists () { type "$1" >/dev/null 2>&1 ; }
+trycc () { test -z "$CC" && cmdexists "$1" && CC=$1 ; }
+
+stripdir () {
+while eval "fnmatch '*/' \"\${$1}\"" ; do eval "$1=\${$1%/}" ; done
+}
+
+trycppif () {
+printf "checking preprocessor condition %s... " "$1"
+echo "typedef int x;" > "$tmpc"
+echo "#if $1" >> "$tmpc"
+echo "#error yes" >> "$tmpc"
+echo "#endif" >> "$tmpc"
+if $CC $2 -c -o "$tmpo" "$tmpc" >/dev/null 2>&1 ; then
+printf "false\n"
+return 1
+else
+printf "true\n"
+return 0
+fi
+}
+
+tryflag () {
+printf "checking whether compiler accepts %s... " "$2"
+echo "typedef int x;" > "$tmpc"
+if $CC $CFLAGS_TRY $2 -c -o "$tmpo" "$tmpc" >/dev/null 2>&1 ; then
+printf "yes\n"
+eval "$1=\"\${$1} \$2\""
+eval "$1=\${$1# }"
+return 0
+else
+printf "no\n"
+return 1
+fi
+}
+
+tryldflag () {
+printf "checking whether linker accepts %s... " "$2"
+echo "typedef int x;" > "$tmpc"
+if $CC $LDFLAGS_TRY -nostdlib -shared "$2" -o "$tmpo" "$tmpc" >/dev/null 2>&1 ; then
+printf "yes\n"
+eval "$1=\"\${$1} \$2\""
+eval "$1=\${$1# }"
+return 0
+else
+printf "no\n"
+return 1
+fi
+}
+
+# Beginning of actual script
+
+CFLAGS_AUTO=
+CFLAGS_TRY=
+LDFLAGS_AUTO=
+LDFLAGS_TRY=
+SRCDIR=
+PREFIX=/usr/local
+EXEC_PREFIX='$(PREFIX)'
+BINDIR='$(EXEC_PREFIX)/bin'
+MANDIR='$(PREFIX)/share/man'
+
+for arg ; do
+case "$arg" in
+--help|-h) usage ;;
+--srcdir=*) SRCDIR=${arg#*=} ;;
+--prefix=*) PREFIX=${arg#*=} ;;
+--exec-prefix=*) EXEC_PREFIX=${arg#*=} ;;
+--bindir=*) BINDIR=${arg#*=} ;;
+--sharedir=*) SHAREDIR=${arg#*=} ;;
+--docdir=*) DOCDIR=${arg#*=} ;;
+--mandir=*) MANDIR=${arg#*=} ;;
+--enable-*|--disable-*|--with-*|--without-*|--*dir=*|--build=*) ;;
+-* ) echo "$0: unknown option $arg" ;;
+CC=*) CC=${arg#*=} ;;
+CFLAGS=*) CFLAGS=${arg#*=} ;;
+CPPFLAGS=*) CPPFLAGS=${arg#*=} ;;
+LDFLAGS=*) LDFLAGS=${arg#*=} ;;
+*=*) ;;
+*) ;;
+esac
+done
+
+for i in SRCDIR PREFIX EXEC_PREFIX BINDIR MANDIR ; do
+stripdir $i
+done
+
+#
+# Get the source dir for out-of-tree builds
+#
+if test -z "$SRCDIR" ; then
+SRCDIR="${0%/configure}"
+stripdir SRCDIR
+fi
+abs_builddir="$(pwd)" || fail "$0: cannot determine working directory"
+abs_srcdir="$(cd $SRCDIR && pwd)" || fail "$0: invalid source directory $SRCDIR"
+test "$abs_srcdir" = "$abs_builddir" && SRCDIR=.
+test "$SRCDIR" != "." -a -f Makefile -a ! -h Makefile && fail "$0: Makefile already exists in the working directory"
+
+#
+# Get a temp filename we can use
+#
+i=0
+set -C
+while : ; do i=$(($i+1))
+tmpc="./conf$$-$PPID-$i.c"
+tmpo="./conf$$-$PPID-$i.o"
+2>|/dev/null > "$tmpc" && break
+test "$i" -gt 50 && fail "$0: cannot create temporary file $tmpc"
+done
+set +C
+trap 'rm -f "$tmpc" "$tmpo"' EXIT INT QUIT TERM HUP
+
+#
+# Find a C compiler to use
+#
+printf "checking for C compiler... "
+trycc cc
+trycc gcc
+trycc clang
+printf "%s\n" "$CC"
+test -n "$CC" || { echo "$0: cannot find a C compiler" ; exit 1 ; }
+
+printf "checking whether C compiler works... "
+echo "typedef int x;" > "$tmpc"
+if output=$($CC $CPPFLAGS $CFLAGS -c -o "$tmpo" "$tmpc" 2>&1) ; then
+printf "yes\n"
+else
+printf "no; compiler output follows:\n%s\n" "$output"
+exit 1
+fi
+
+#
+# Figure out options to force errors on unknown flags.
+#
+tryflag   CFLAGS_TRY  -Werror=unknown-warning-option
+tryflag   CFLAGS_TRY  -Werror=unused-command-line-argument
+tryldflag LDFLAGS_TRY -Werror=unknown-warning-option
+tryldflag LDFLAGS_TRY -Werror=unused-command-line-argument
+
+CFLAGS_STD="-std=c99 -D_POSIX_C_SOURCE=200809L -D_XOPEN_SOURCE=700 -DNDEBUG -D_FORTIFY_SOURCE=2"
+LDFLAGS_STD="-lc -lutil"
+
+OS=$(uname)
+
+case "$OS" in
+FreeBSD) CFLAGS_STD="$CFLAGS_STD -D_BSD_SOURCE -D__BSD_VISIBLE=1" ;;
+*BSD)    CFLAGS_STD="$CFLAGS_STD -D_BSD_SOURCE" ;;
+Darwin)  CFLAGS_STD="$CFLAGS_STD -D_DARWIN_C_SOURCE" ;;
+AIX)     CFLAGS_STD="$CFLAGS_STD -D_ALL_SOURCE" ;;
+esac
+
+tryflag CFLAGS -pipe
+
+# Try flags to optimize binary size
+tryflag CFLAGS -Os
+tryflag CFLAGS -ffunction-sections
+tryflag CFLAGS -fdata-sections
+tryldflag LDFLAGS_AUTO -Wl,--gc-sections
+
+# Try hardening flags
+tryflag CFLAGS -fPIE
+tryflag CFLAGS_AUTO -fstack-protector-all
+tryldflag LDFLAGS -Wl,-z,now
+tryldflag LDFLAGS -Wl,-z,relro
+tryldflag LDFLAGS_AUTO -pie
+
+printf "creating config.mk... "
+
+cmdline=$(quote "$0")
+for i ; do cmdline="$cmdline $(quote "$i")" ; done
+
+exec 3>&1 1>config.mk
+
+cat << EOF
+# This version of config.mk was generated by:
+# $cmdline
+# Any changes made here will be lost if configure is re-run
+SRCDIR = $SRCDIR
+PREFIX = $PREFIX
+EXEC_PREFIX = $EXEC_PREFIX
+BINDIR = $BINDIR
+MANPREFIX = $MANDIR
+CC = $CC
+CFLAGS = $CFLAGS
+LDFLAGS = $LDFLAGS
+CFLAGS_STD = $CFLAGS_STD
+LDFLAGS_STD = $LDFLAGS_STD
+CFLAGS_AUTO = $CFLAGS_AUTO
+LDFLAGS_AUTO = $LDFLAGS_AUTO
+CFLAGS_DEBUG = -U_FORTIFY_SOURCE -UNDEBUG -O0 -g -ggdb -Wall -Wextra -pedantic -Wno-unused-parameter -Wno-sign-compare
+EOF
+exec 1>&3 3>&-
+
+printf "done\n"
+
+test "$SRCDIR" = "." || ln -sf $SRCDIR/Makefile .

contrib/abduco.zsh

@@ -0,0 +1,35 @@
+#compdef abduco
+
+typeset -A opt_args
+
+_abduco_sessions() {
+  declare -a sessions
+  sessions=( $(abduco | sed '1d;s/.*\t[0-9][0-9]*\t//') )
+  _describe -t session 'session' sessions
+}
+
+_abduco_firstarg() {
+  if (( $+opt_args[-a] || $+opt_args[-A] )); then
+    _abduco_sessions
+  elif (( $+opt_args[-c] || $+opt_args[-n] )); then
+    _guard "^-*" 'session name'
+  elif [[ -z $words[CURRENT] ]]; then
+    compadd "$@" -S '' -- -
+  fi
+}
+
+_arguments -s \
+  '(-a -A -c -n -f)-a[attach to an existing session]' \
+  '(-a -A -c -n)-A[attach to a session, create if does not exist]' \
+  '(-a -A -c -n -l)-c[create a new session and attach to it]' \
+  '(-a -A -c -n -l)-n[create a new session but do not attach to it]' \
+  '-e[set the detachkey (default: ^\\)]:detachkey' \
+  '(-a)-f[force create the session]' \
+  '(-q)-p[pass-through mode]' \
+  '-q[be quiet]' \
+  '-r[read-only session, ignore user input]' \
+  '(-c -n)-l[attach with the lowest priority]' \
+  '(-)-v[show version information and exit]' \
+  '1: :_abduco_firstarg' \
+  '2:command:_path_commands' \
+  '*:: :{ shift $((CURRENT-3)) words; _precommand; }'

debug.c

@@ -16,8 +16,8 @@ static void print_packet(const char *prefix, Packet *pkt) {
 		[MSG_ATTACH]  = "ATTACH",
 		[MSG_DETACH]  = "DETACH",
 		[MSG_RESIZE]  = "RESIZE",
-		[MSG_REDRAW]  = "REDRAW",
 		[MSG_EXIT]    = "EXIT",
+		[MSG_PID]     = "PID",
 	};
 	const char *type = "UNKNOWN";
 	if (pkt->type < countof(msgtype) && msgtype[pkt->type])
@@ -26,14 +26,24 @@ static void print_packet(const char *prefix, Packet *pkt) {
 	fprintf(stderr, "%s: %s ", prefix, type);
 	switch (pkt->type) {
 	case MSG_CONTENT:
-		for (size_t i = 0; i < pkt->len && i < sizeof(pkt->u.msg); i++)
-			fprintf(stderr, "%c", pkt->u.msg[i]);
+		fwrite(pkt->u.msg, pkt->len, 1, stderr);
 		break;
 	case MSG_RESIZE:
-		fprintf(stderr, "%dx%d", pkt->u.ws.ws_col, pkt->u.ws.ws_row);
+		fprintf(stderr, "%"PRIu16"x%"PRIu16, pkt->u.ws.cols, pkt->u.ws.rows);
+		break;
+	case MSG_ATTACH:
+		fprintf(stderr, "readonly: %d low-priority: %d",
+			pkt->u.i & CLIENT_READONLY,
+			pkt->u.i & CLIENT_LOWPRIORITY);
+		break;
+	case MSG_EXIT:
+		fprintf(stderr, "status: %"PRIu32, pkt->u.i);
+		break;
+	case MSG_PID:
+		fprintf(stderr, "pid: %"PRIu32, pkt->u.i);
 		break;
 	default:
-		fprintf(stderr, "len: %zu", pkt->len);
+		fprintf(stderr, "len: %"PRIu32, pkt->len);
 		break;
 	}
 	fprintf(stderr, "\n");

server.c

@@ -18,6 +18,18 @@ static void client_free(Client *c) {
 	free(c);
 }
 
+static void server_sink_client() {
+	if (!server.clients || !server.clients->next)
+		return;
+	Client *target = server.clients;
+	server.clients = target->next;
+	Client *dst = server.clients;
+	while (dst->next)
+		dst = dst->next;
+	target->next = NULL;
+	dst->next = target;
+}
+
 static void server_mark_socket_exec(bool exec, bool usr) {
 	struct stat sb;
 	if (stat(sockaddr.sun_path, &sb) == -1)
@@ -63,33 +75,14 @@ static int server_set_socket_non_blocking(int sock) {
     	return fcntl(sock, F_SETFL, flags | O_NONBLOCK);
 }
 
-static Client *server_accept_client(void) {
-	int newfd = accept(server.socket, NULL, NULL);
-	if (newfd == -1 || server_set_socket_non_blocking(newfd) == -1)
-		goto error;
-	Client *c = client_malloc(newfd);
-	if (!c)
-		goto error;
-	if (!server.clients)
-		server_mark_socket_exec(true, true);
-	c->socket = newfd;
-	c->state = STATE_CONNECTED;
-	c->next = server.clients;
-	server.clients = c;
-	server.read_pty = true;
-	return c;
-error:
-	if (newfd != -1)
-		close(newfd);
-	return NULL;
-}
-
 static bool server_read_pty(Packet *pkt) {
 	pkt->type = MSG_CONTENT;
 	ssize_t len = read(server.pty, pkt->u.msg, sizeof(pkt->u.msg));
-	if (len != -1)
+	if (len > 0)
 		pkt->len = len;
-	else if (errno != EAGAIN && errno != EINTR)
+	else if (len == 0)
+		server.running = false;
+	else if (len == -1 && errno != EAGAIN && errno != EINTR && errno != EWOULDBLOCK)
 		server.running = false;
 	print_packet("server-read-pty:", pkt);
 	return len > 0;
@@ -143,6 +136,35 @@ static void server_sigterm_handler(int sig) {
 	exit(EXIT_FAILURE); /* invoke atexit handler */
 }
 
+static Client *server_accept_client(void) {
+	int newfd = accept(server.socket, NULL, NULL);
+	if (newfd == -1 || server_set_socket_non_blocking(newfd) == -1)
+		goto error;
+	Client *c = client_malloc(newfd);
+	if (!c)
+		goto error;
+	if (!server.clients)
+		server_mark_socket_exec(true, true);
+	c->socket = newfd;
+	c->state = STATE_CONNECTED;
+	c->next = server.clients;
+	server.clients = c;
+	server.read_pty = true;
+
+	Packet pkt = {
+		.type = MSG_PID,
+		.len = sizeof pkt.u.l,
+		.u.l = getpid(),
+	};
+	server_send_packet(c, &pkt);
+
+	return c;
+error:
+	if (newfd != -1)
+		close(newfd);
+	return NULL;
+}
+
 static void server_sigusr1_handler(int sig) {
 	int socket = server_create_socket(server.session_name);
 	if (socket != -1) {
@@ -201,19 +223,25 @@ static void server_mainloop(void) {
 					server_write_pty(&client_packet);
 					break;
 				case MSG_ATTACH:
-					c->readonly = client_packet.u.b;
+					c->flags = client_packet.u.i;
+					if (c->flags & CLIENT_LOWPRIORITY)
+						server_sink_client();
 					break;
 				case MSG_RESIZE:
 					c->state = STATE_ATTACHED;
-				case MSG_REDRAW:
-					if (!c->readonly && (client_packet.type == MSG_REDRAW || c == server.clients)) {
+					if (!(c->flags & CLIENT_READONLY) && c == server.clients) {
 						debug("server-ioct: TIOCSWINSZ\n");
-						ioctl(server.pty, TIOCSWINSZ, &client_packet.u.ws);
+						struct winsize ws = { 0 };
+						ws.ws_row = client_packet.u.ws.rows;
+						ws.ws_col = client_packet.u.ws.cols;
+						ioctl(server.pty, TIOCSWINSZ, &ws);
 					}
 					kill(-server.pid, SIGWINCH);
 					break;
-				case MSG_DETACH:
 				case MSG_EXIT:
+					exit_packet_delivered = true;
+					/* fall through */
+				case MSG_DETACH:
 					c->state = STATE_DISCONNECTED;
 					break;
 				default: /* ignore package */
@@ -249,9 +277,7 @@ static void server_mainloop(void) {
 						.u.i = server.exit_status,
 						.len = sizeof(pkt.u.i),
 					};
-					if (server_send_packet(c, &pkt))
-						exit_packet_delivered = true;
-					else
+					if (!server_send_packet(c, &pkt))
 						FD_SET_MAX(c->socket, &new_writefds, new_fdmax);
 				} else {
 					FD_SET_MAX(c->socket, &new_writefds, new_fdmax);

testsuite.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 
 ABDUCO="./abduco"
 # set detach key explicitly in case it was changed in config.h
@@ -7,6 +7,9 @@ ABDUCO_OPTS="-e ^\\"
 [ ! -z "$1" ] && ABDUCO="$1"
 [ ! -x "$ABDUCO" ] && echo "usage: $0 /path/to/abduco" && exit 1
 
+TESTS_OK=0
+TESTS_RUN=0
+
 detach() {
 	sleep 1
 	printf ""
@@ -27,7 +30,7 @@ dvtm_session() {
 	dvtm_cmd ' '
 	dvtm_cmd ' '
 	sleep 1
-	dvtm_cmd 'q'
+	dvtm_cmd 'qq'
 }
 
 expected_abduco_prolog() {
@@ -36,7 +39,7 @@ expected_abduco_prolog() {
 
 # $1 => session-name, $2 => exit status
 expected_abduco_epilog() {
-	echo "[?1049labduco: $1: session terminated with exit status $2"
+	echo "[?25h[?1049labduco: $1: session terminated with exit status $2"
 }
 
 # $1 => session-name, $2 => cmd to run
@@ -49,7 +52,7 @@ expected_abduco_attached_output() {
 # $1 => session-name, $2 => cmd to run
 expected_abduco_detached_output() {
 	expected_abduco_prolog
-	$2 &> /dev/null
+	$2 >/dev/null 2>&1
 	expected_abduco_epilog "$1" $?
 }
 
@@ -61,7 +64,7 @@ check_environment() {
 
 test_non_existing_command() {
 	check_environment || return 1;
-	$ABDUCO -c test ./non-existing-command &> /dev/null
+	$ABDUCO -c test ./non-existing-command >/dev/null 2>&1
 	check_environment || return 1;
 }
 
@@ -74,12 +77,14 @@ run_test_attached() {
 	local output="$name.out"
 	local output_expected="$name.expected"
 
+	TESTS_RUN=$((TESTS_RUN + 1))
 	echo -n "Running test attached: $name "
-	expected_abduco_attached_output "$name" "$cmd" &> "$output_expected"
-	$ABDUCO -c "$name" $cmd 2>&1 | sed 's/.$//' > "$output"
+	expected_abduco_attached_output "$name" "$cmd" > "$output_expected" 2>&1
 
-	if diff -u "$output_expected" "$output" && check_environment; then
+	if $ABDUCO -c "$name" $cmd 2>&1 | sed 's/.$//' > "$output" && sleep 1 &&
+	   diff -u "$output_expected" "$output" && check_environment; then
 		rm "$output" "$output_expected"
+		TESTS_OK=$((TESTS_OK + 1))
 		echo "OK"
 		return 0
 	else
@@ -97,13 +102,15 @@ run_test_detached() {
 	local output="$name.out"
 	local output_expected="$name.expected"
 
+	TESTS_RUN=$((TESTS_RUN + 1))
 	echo -n "Running test detached: $name "
-	expected_abduco_detached_output "$name" "$cmd" &> "$output_expected"
+	expected_abduco_detached_output "$name" "$cmd" > "$output_expected" 2>&1
 
-	if $ABDUCO -n "$name" $cmd &> /dev/null && sleep 1 &&
+	if $ABDUCO -n "$name" $cmd >/dev/null 2>&1 && sleep 1 &&
 	   $ABDUCO -a "$name" 2>&1 | sed 's/.$//' > "$output" &&
 	   diff -u "$output_expected" "$output" && check_environment; then
 		rm "$output" "$output_expected"
+		TESTS_OK=$((TESTS_OK + 1))
 		echo "OK"
 		return 0
 	else
@@ -121,14 +128,16 @@ run_test_attached_detached() {
 	local output="$name.out"
 	local output_expected="$name.expected"
 
+	TESTS_RUN=$((TESTS_RUN + 1))
 	echo -n "Running test: $name "
-	$cmd &> /dev/null
-	expected_abduco_epilog "$name" $? &> "$output_expected"
+	$cmd >/dev/null 2>&1
+	expected_abduco_epilog "$name" $? > "$output_expected" 2>&1
 
-	if detach | $ABDUCO $ABDUCO_OPTS -c "$name" $cmd &> /dev/null && sleep 3 &&
+	if detach | $ABDUCO $ABDUCO_OPTS -c "$name" $cmd >/dev/null 2>&1 && sleep 3 &&
 	   $ABDUCO -a "$name" 2>&1 | tail -1 | sed 's/.$//' > "$output" &&
 	   diff -u "$output_expected" "$output" && check_environment; then
 		rm "$output" "$output_expected"
+		TESTS_OK=$((TESTS_OK + 1))
 		echo "OK"
 		return 0
 	else
@@ -139,22 +148,21 @@ run_test_attached_detached() {
 
 run_test_dvtm() {
 	echo -n "Running dvtm test: "
-	if ! which dvtm &> /dev/null; then
+	if ! which dvtm >/dev/null 2>&1; then
 		echo "SKIPPED"
 		return 0;
 	fi
 
+	TESTS_RUN=$((TESTS_RUN + 1))
 	local name="dvtm"
 	local output="$name.out"
 	local output_expected="$name.expected"
 
-	echo exit | dvtm &> /dev/null
-	expected_abduco_epilog "$name" $? > "$output_expected"
-	local len=`wc -c "$output_expected"  | awk '{ print $1 }'`
-	len=$((len+1))
-	if dvtm_session | $ABDUCO -c "$name" 2>&1 | tail -c $len | sed 's/.$//' > "$output" &&
+	: > "$output_expected"
+	if dvtm_session | $ABDUCO -c "$name" > "$output" 2>&1 &&
 	   diff -u "$output_expected" "$output" && check_environment; then
 		rm "$output" "$output_expected"
+		TESTS_OK=$((TESTS_OK + 1))
 		echo "OK"
 		return 0
 	else
@@ -165,8 +173,8 @@ run_test_dvtm() {
 
 test_non_existing_command || echo "Execution of non existing command FAILED"
 
-run_test_attached "seq" "seq 1 1000"
-run_test_detached "seq" "seq 1 1000"
+run_test_attached "awk" "awk 'BEGIN {for(i=1;i<=1000;i++) print i}'"
+run_test_detached "awk" "awk 'BEGIN {for(i=1;i<=1000;i++) print i}'"
 
 run_test_attached "false" "false"
 run_test_detached "false" "false"
@@ -203,3 +211,5 @@ run_test_attached_detached "attach-detach" "./long-running.sh"
 rm ./long-running.sh
 
 run_test_dvtm
+
+[ $TESTS_OK -eq $TESTS_RUN ]