Test "--watchfd PID".

2024-11-30 22:55:00 +00:00
parent e8cc443681
commit fa745f2cfe
2 changed files with 74 additions and 0 deletions
@@ -0,0 +1,73 @@
+#!/bin/sh
+#
+# Check that watching a process's file descriptors works as expected.
+
+# Dummy assignments for "shellcheck".
+testSubject="${testSubject:-false}"; workFile1="${workFile1:-.tmp1}"; workFile2="${workFile2:-.tmp2}"; workFile3="${workFile3:-.tmp3}"
+
+# Skip the test if "-d" is not available.
+if ! "${testSubject}" -h | grep -Fq ' -d'; then
+	echo "no \`--watchfd' / \`-d' option on this platform"
+	exit 77
+fi
+
+seq 1 100 > "${workFile1}"
+seq 1 300 > "${workFile2}"
+
+# Run a background process to perform a few reads from a file, opening a
+# second file after a moment.
+# NB we just export line to make shellcheck think it's used.
+(
+export line
+sleep 1
+read -r line
+exec 9<"${workFile2}"
+sleep 1
+read -r line
+sleep 1
+) <"${workFile1}" &
+pid=$!
+
+sleep 0.1
+"${testSubject}" -d "${pid}" -f -i 0.5 >/dev/null 2>"${workFile3}"
+
+# Skip the test if "-d" does not work.
+if grep -Fq ' -d: not available' "${workFile3}"; then
+	echo "no \`--watchfd' / \`-d' option on this platform"
+	exit 77
+fi
+
+# Process the output to make it easier to handle.
+# NB "ESC [ A" is "cursor up", we turn that into "-" and a newline.
+tr '\r' '\n' < "${workFile3}" | sed 's/.\[A/-!/g' | tr '!' '\n' > "${workFile1}"
+
+# We should see at least 2 file positions for fd 0.
+positionsReported="$(awk '/^ *0:/ {print $2}' < "${workFile1}" | sort -n | uniq)"
+differentNumbers="$(printf "%s\n" "${positionsReported}" | grep -Ec .)"
+if ! test "${differentNumbers}" -gt 1; then
+	printf "%s\n" "Expected at least 2 different numbers to be output for fd 0"
+	printf "%s:\n%s\n" "Positions reported" "${positionsReported}"
+	printf "%s: %s\n" "Number of different values seen" "${differentNumbers}"
+	printf "%s\n" "Raw output:"
+	cat "${workFile1}"
+	exit 1
+fi
+
+# We should see file descriptor 9 appear.
+if ! grep -Eq '^ *9:' < "${workFile1}"; then
+	printf "%s\n" "Expected to see information for fd 9"
+	printf "%s\n" "Raw output:"
+	cat "${workFile1}"
+	exit 1
+fi
+
+# We should see the last 6 characters of fd 9's filename appear.
+lastChars="$(printf "%s\n" "${workFile2}" | rev | cut -b1-6 | rev)"
+if ! grep -Fq "${lastChars}:" < "${workFile1}"; then
+	printf "%s\n" "Expected to see a filename for fd 9"
+	printf "%s\n" "Raw output:"
+	cat "${workFile1}"
+	exit 1
+fi
+
+exit 0