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i am studying shell script right now. I started to learn how to work with more complex if statements. What's wrong with this code bellow? I read other similar questions here in stackoverflow, but i couldnt resolve my problem. Now im verifying if the first, second or third argument is null. In the future i pretend to verify based in some regex or something like that.
Thanks!!

The code (line 9):

if [ "$1" -eq "" ] || [ "$2" -eq "" ] || [ "$3" -eq "" ] then ...

line 9: [: : integer expression expected
line 9: [: : integer expression expected
line 9: [: : integer expression expected

Barmar
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Pedro Detona
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2 Answers2

2

-eq performs an arithmetic comparison between two numbers. Use = for string comparisons. Or better yet, use [[ and ==.

[[ $1 == "" ]]
[ "$1" = "" ]

You can also use -z and -n to directly test whether a value is empty/non-empty.

[[ -n $value ]]    # [[ $value != "" ]]
[[ -z $value ]]    # [[ $value == "" ]]
John Kugelman
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-1

use [[ and ]] for the more modern / complex operators. This is a bashism, so beware.

Jake H
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