From 40b2714221ab22163419308b0d0322fd3ea64c82 Mon Sep 17 00:00:00 2001
From: "Ingraham, Daniel James (GRC-LTV0)" <daniel.j.ingraham@nasa.gov>
Date: Thu, 23 Sep 2021 19:34:17 -0400
Subject: [PATCH] Add -d flag to detect if a session exists

---
 abduco.1     |  6 ++++++
 abduco.c     | 10 +++++++++-
 testsuite.sh | 28 ++++++++++++++++++++++++++++
 3 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/abduco.1 b/abduco.1
index c122308..a828417 100644
--- a/abduco.1
+++ b/abduco.1
@@ -25,6 +25,10 @@
 .Cm command Op args ...
 .
 .Nm
+.Fl d
+.Cm name
+.
+.Nm
 .Fl n
 .Op options ...
 .Cm name
@@ -84,6 +88,8 @@ Attach to an existing session.
 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 d
+Detect if the specified session exists, returning a successful exit status if true.
 .It Fl n
 Create a new session but do not attach to it.
 .El
diff --git a/abduco.c b/abduco.c
index b56e6f4..7f0dfc3 100644
--- a/abduco.c
+++ b/abduco.c
@@ -606,11 +606,12 @@ int main(int argc, char *argv[]) {
 	server.name = basename(argv[0]);
 	gethostname(server.host+1, sizeof(server.host) - 1);
 
-	while ((opt = getopt(argc, argv, "aAclne:fpqrv")) != -1) {
+	while ((opt = getopt(argc, argv, "aAcdlne:fpqrv")) != -1) {
 		switch (opt) {
 		case 'a':
 		case 'A':
 		case 'c':
+		case 'd':
 		case 'n':
 			action = opt;
 			break;
@@ -712,6 +713,13 @@ int main(int argc, char *argv[]) {
 			goto redo;
 		}
 		break;
+    case 'd':
+        if (session_exists(server.session_name)) {
+            return EXIT_SUCCESS;
+        } else {
+            return EXIT_FAILURE;
+        }
+        break;
 	}
 
 	return 0;
diff --git a/testsuite.sh b/testsuite.sh
index d6c73be..92594d5 100755
--- a/testsuite.sh
+++ b/testsuite.sh
@@ -171,6 +171,33 @@ run_test_dvtm() {
 	fi
 }
 
+run_test_detect_session() {
+	check_environment || return 1;
+
+	local name="$1"
+    local cmd="$2"
+	local output="$name.out"
+	local output_expected="$name.expected"
+
+	TESTS_RUN=$((TESTS_RUN + 1))
+	echo -n "Running test: $name "
+	$cmd >/dev/null 2>&1
+	expected_abduco_epilog "$name" $? > "$output_expected" 2>&1
+
+	if detach | $ABDUCO $ABDUCO_OPTS -c "$name" $cmd >/dev/null 2>&1 && sleep 3 &&
+       $ABDUCO -d "$name" &&
+	   $ABDUCO -a "$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
+		echo "FAIL"
+		return 1
+	fi
+}
+
 test_non_existing_command || echo "Execution of non existing command FAILED"
 
 run_test_attached "awk" "awk 'BEGIN {for(i=1;i<=1000;i++) print i}'"
@@ -207,6 +234,7 @@ EOT
 chmod +x long-running.sh
 
 run_test_attached_detached "attach-detach" "./long-running.sh"
+run_test_detect_session "detect-session" "./long-running.sh"
 
 rm ./long-running.sh