I am trying to write a shell script to read username from a file, but it is not working. I am posting script I am writing and output

Question

#!/bin/bash
if [ -f "$1" ]
then
    for users in 'cat $1'
    do
        useradd $users
    done
else
    echo "input is not a file"
fi

Please post output as text and not as links or images - [reasoning](https://meta.stackoverflow.com/questions/285551/why-not-upload-images-of-code-on-so-when-asking-a-question) — kaylum, Jan 30 '20 at 09:52
Single quotes is not what you want. `'cat $1'` --> `$(cat $1)` or `\`cat $1\`` — kaylum, Jan 30 '20 at 09:54
To substitute a command's output, that is `cat $1` here, we don't use single quotes; the correct syntax is `\`cat $1\`` or `$(cat $1)`, latter is more convenient — oguz ismail, Jan 30 '20 at 09:55

score 0 · Accepted Answer · answered Jan 30 '20 at 10:16

0

You just have to get the input for the do loop right:

#!/bin/bash
if [ -f "$1" ]
then
    for user in $(cat "$1")
    do
        useradd "$user"
    done
else
    echo "input is not a file"
fi

Remarks: this works for reading out a file word-by-word and I tried to keep your structure.

For reading out files line by line this is an elegant way: https://stackoverflow.com/a/4642213/2819581

answered Jan 30 '20 at 10:16

Jonas Eberle

Hi Jonas Eberle, Thanks for sharing this answer. This worked. Thank you for helping. – parth5194 Jan 31 '20 at 12:50

1 Answers1