ps: add notes

2 files changed, 37 insertions, 0 deletions

diff --git a/src/monitor/README.md b/src/monitor/README.md
index baaacb9..4728b14 100644
--- a/src/monitor/README.md
+++ b/src/monitor/README.md
@@ -4,5 +4,6 @@
 - [ss](./ss.md)
 - [pidstat](./pidstat.md)
 - [pgrep](./pgrep.md)
+- [ps](./ps.md)
 - [pmap](./pmap.md)
 - [pstack](./pstack.md)
diff --git a/src/monitor/ps.md b/src/monitor/ps.md
new file mode 100644
index 0000000..7e86678
--- /dev/null
+++ b/src/monitor/ps.md
@@ -0,0 +1,36 @@
+# ps(1)
+
+```
+ps [opt]
+  opt:
+    --no-header .... do not print column header
+    -o <OUT> ....... comma separated list of output columns
+    -p <PID> ....... only show pid
+    -T ............. list threads
+```
+> Set `PS_FORMAT` env variable to setup default output columns.
+
+Frequently used output columns
+```
+pid        process id
+pgid       process group id
+tid        thread id
+
+comm       name of process
+cmd        name of process + args (full)
+
+etime      elapsed time (since process started)
+user       user owning process
+
+pcpu       cpu utilization (percent)
+pmem       physical resident set (rss) (percent)
+rss        physical memory (in kb)
+vsz        virtual memory (in kb)
+```
+
+## Example: Use output for scripting
+```sh
+for tid in $(ps -o tid --no-header -T -p 31084); do
+    taskset -c -p $tid;
+done
+```