Multiple conditions with if in shell scripting

Question

I want to check if a file exists or not along with the no of lines = 4 in a single if condition . Can anyone help here.

if [[ -f report]] && [[`wc -l report` -eq 4 ]]; then
    echo " Proceed further"
else
    exit 1
fi

shellcheck.net will tell you what's wrong with your conditions. — Benjamin W.
– Benjamin W., Commented Jul 22, 2018 at 3:38

agc · Accepted Answer · 2018-07-22 04:29:14Z

1

This is simpler:

{ [ `wc -l < report` -eq 4 ] || exit; } 2>/dev/null 
echo " Proceed further"

Notes:

If report exists and is 4 lines long, then wc -l report returns:
```
4 report
```
...which -eq can't understand. Instead do wc -l < report which outputs an -eq-friendly:
```
4
```
There's no need to check if report exists, since the < redirection will do that anyway, and returns the same error code.
More specific exit codes. If report does not exist, the exit code is 2. If report is 5 lines long, the exit code is 1.

answered Jul 22, 2018 at 4:08

agc

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3 Comments

My objective here is to exit from script if the count is not equals to 4. How to add that

@John, see revised answer.