Bash - creating a variable out of the printed ls - bash

Question

Im struggling with creating a bash script similiar to ps.
I just can't get it how bash works and how to make it work. Worst thing, it's first language that I don't even know how to start with and the pressure from college is making only things worse.
My plan is:
Create a while loop
Trough all the stuff of "ls /proc"
Create a variable out of found folder like "folder=$(awk '{print $i}')"
Printf the created variable and some stuff about if from /proc/i/status
End while loop if something happend to be not an integer.
And I just can't get it. Im facing tons of problems and googling them hard as usually when I start to learn a new language isn't helping to solve anything. I feel helpless with this task. I don't even know if my approuch to the problem is right :(

Answer 1

You don't need or want to parse ls output. Just loop over a wildcard directly.
for proc in /proc/*; do
pid=${proc#/proc/}
case $pid in *[!0-9]*) break;; esac
awk -v pid="pid" '{ printf "%i %s\n", pid, "stuff" }' $proc/status
done
You might want continue instead of break but the shell will alphabetize the hits when expanding the wildcard so the numeric entries will actually be grouped before other entries.
The parameter expansion ${variable#pattern} produces the value of variable with any leading match on pattern trimmed off. There is also ${variable%suffix} to trim a suffix matching a pattern, and a number of other simple string manipulation facilities.

Answer 2

You're not saying what exactly you want to extract from the process status, so let's say you want it's name and state
Borrowing from #tripleee answer, you could do:
#!/bin/sh
for proc in /proc/*
do
pid=${proc#/proc/}
case $pid in *[!0-9]*) continue;; esac
name=$(grep "Name" $proc/status | awk '{print $2$3}')
state=$(grep "State" $proc/status | awk '{print $2 " " $3}')
echo $proc $name $state | awk '{print $1 ", whose name is " $2 " is in state " $3 " " $4}'
done
Which would print something like:
/proc/98, whose name is kthrotld is in state I (idle)
/proc/9813, whose name is WebContent is in state S (sleeping)
/proc/99, whose name is acpi_thermal_pm is in state I (idle)
Or, if you want to get fancy, you could print with some color:
#!/bin/sh
for proc in /proc/*
do
pid=${proc#/proc/}
case $pid in *[!0-9]*) continue;; esac
name=$(grep "Name" $proc/status | awk '{print $2$3}')
state=$(grep "State" $proc/status | awk '{print $2 " " $3}')
echo $proc $name $state | awk '{print "\033[0;33m" $1 "\033[0;m, whose name is " "\033[0;32m" $2 "\033[0m is in state \033[0;34m" $3 " " $4 "\033[0m"}'
done
Which would output something like