How do I find all the occurance of a particular text in a file with a shell script. (Not using grep command)

CodePudding user response：

awk '/^admin/ {print NR;}' /etc/passwd

CodePudding user response：

A POSIX shell-only solution could be

n=0
while n=$((n 1)); IFS=':' read -r u _
do
  case "$u" in
    admin*) echo $n;;
  esac
done < /etc/passwd