From 1bf05d0972b043ef4e65c812bcbc4c11b2d6cbdb Mon Sep 17 00:00:00 2001
From: Narvin Singh <Narvin.A.Singh@gmail.com>
Date: Mon, 25 Oct 2021 22:29:52 -0400
Subject: [PATCH] Feat: Return a PID in edge cases
- Return the first ancestor PID if root_name is not found.
- Return the process' own PID if its own name is root_name.
---
rpid | 28 ++++++++++++++++++++++------
1 file changed, 22 insertions(+), 6 deletions(-)
diff --git a/rpid b/rpid
index b1f2b71..c957f84 100755
--- a/rpid
+++ b/rpid
@@ -21,6 +21,16 @@ EXAMPLES:
process.
rpid $$
+
+ Get the PID of the first ancestor of the current process, if there
+ is no ancestor named "not_a_process."
+
+ rpid $$ not_a_process
+
+ Get the PID of the current process itself, if it is named
+ "current_process."
+
+ rpid $$ current_process
'
# Validate the arguments
@@ -51,13 +61,19 @@ get_info() {
ppid="${ppid%%[[:space:]]}"
}
-next_pid="${pid}"
-while [[ "${name}" != "${root_name}" && "${ppid}" -ne 1 ]]; do
- get_info "${next_pid}";
- name_pid="${next_pid}"
- next_pid="${ppid}"
+prev_pid="${pid}"
+current_pid="${pid}"
+while [[ "${name}" != "${root_name}" && -r "/proc/${current_pid}/status" ]]; do
+ mapfile info < \
+ <(grep --null -E -m 2 '^(Name|PPid):' "/proc/${current_pid}/status" \
+ | sort | cut -f 2)
+ name="${info[0]##[[:space:]]}"
+ name="${name%%[[:space:]]}"
+ prev_pid="${current_pid}"
+ current_pid="${info[1]##[[:space:]]}"
+ current_pid="${current_pid%%[[:space:]]}"
done
+printf '%s\n' "${prev_pid}"
if [[ "${name}" != "${root_name}" ]]; then exit 1; fi
-printf '%s\n' "${name_pid}"