Bash script to get specific user(s) id and processes count - linux

Question

I need bash script to count processes of SPECIFIC users or all users. We can enter 0, 1 or more arguments. For example
./myScript.sh root deamon
should execute like this:
root 92
deamon 8
2 users has total processes: 100
If nothing is entered as parameter, then all users should be listed:
uuidd 1
awkd 2
daemon 1
root 210
kklmn 6
5 users has total processes: 220
What I have till now is script for all users, and it works fine (with some warnings). I just need part where arguments are entered (some kind of filter results). Here is script for all users:
cntp = 0 #process counter
cntu = 0 #user counter
ps aux |
awk 'NR>1{tot[$1]++; cntp++}
END{for(id in tot){printf "%s\t%4d\n",id,tot[id]; cntu++}
printf "%4d users has total processes:%4d\n", cntu, cntp}'

Answer 1

#!/bin/bash
users=$#
args=()
if [ $# -eq 0 ]; then
# all processes
args+=(ax)
else
# user processes, comma-separated list of users
args+=(-u${users// /,})
fi
# print the user field without header
args+=(-ouser=)
ps "${args[#]}" | awk '
{ tot[$1]++ }
END{ for(id in tot){ printf "%s\t%4d\n", id, tot[id]; cntu++ }
printf "%4d users has total processes:%4d\n", cntu, NR}'
The ps arguments are stored in array args and list either all processes with ax or user processes in the form -uuser1,user2
and -ouser= only lists the user field without header.
In the awk script I only removed the NR>1 test and variable cntp which can be replaced by NR.
Possible invocations:
./myScript.sh
./myScript.sh root daemon
./myScript.sh root,daemon

Answer 2

The following seems to work:
ps axo user |
awk -v args="$(IFS=,; echo "$*")" '
BEGIN {
# split args on comma
split(args, users, ",");
# associative array with user as indexes
for (i in users) {
enabled[users[i]] = 1
}
}
NR > 1 {
tot[$1]++;
cntp++;
}
END {
for(id in tot) {
# if we passed some arguments
# and its disabled
if (length(args) && enabled[id] == 0) {
continue
}
printf "%s\t%4d\n", id, tot[id];
cntu++;
}
printf "%4d users has total processes:%4d\n", cntu, cntp
}
'
Tested in repl.