Using if elif fi in shell scripts
BashShellBash Problem Overview
I'm not sure how to do an if with multiple tests in shell. I'm having trouble writing this script:
echo "You have provided the following arguments $arg1 $arg2 $arg3"
if [ "$arg1" = "$arg2" && "$arg1" != "$arg3" ]
then
echo "Two of the provided args are equal."
exit 3
elif [ $arg1 = $arg2 && $arg1 = $arg3 ]
then
echo "All of the specified args are equal"
exit 0
else
echo "All of the specified args are different"
exit 4
fi
The problem is I get this error every time:
> ./compare.sh: [: missing `]' command not found
Bash Solutions
Solution 1 - Bash
Josh Lee's answer works, but you can use the "&&" operator for better readability like this:
echo "You have provided the following arguments $arg1 $arg2 $arg3"
if [ "$arg1" = "$arg2" ] && [ "$arg1" != "$arg3" ]
then
echo "Two of the provided args are equal."
exit 3
elif [ $arg1 = $arg2 ] && [ $arg1 = $arg3 ]
then
echo "All of the specified args are equal"
exit 0
else
echo "All of the specified args are different"
exit 4
fi
Solution 2 - Bash
sh is interpreting the && as a shell operator. Change it to -a, that’s [’s conjunction operator:
[ "$arg1" = "$arg2" -a "$arg1" != "$arg3" ]
Also, you should always quote the variables, because [ gets confused when you leave off arguments.
Solution 3 - Bash
Use double brackets...
if [[ expression ]]
Solution 4 - Bash
I have a sample from your code. Try this:
echo "*Select Option:*"
echo "1 - script1"
echo "2 - script2"
echo "3 - script3 "
read option
echo "You have selected" $option"."
if [ $option="1" ]
then
echo "1"
elif [ $option="2" ]
then
echo "2"
exit 0
elif [ $option="3" ]
then
echo "3"
exit 0
else
echo "Please try again from given options only."
fi
This should work. :)
Solution 5 - Bash
Change [ to [[, and ] to ]].
Solution 6 - Bash
This is working for me,
# cat checking.sh
#!/bin/bash
echo "You have provided the following arguments $arg1 $arg2 $arg3"
if [ "$arg1" = "$arg2" ] && [ "$arg1" != "$arg3" ]
then
echo "Two of the provided args are equal."
exit 3
elif [ $arg1 == $arg2 ] && [ $arg1 = $arg3 ]
then
echo "All of the specified args are equal"
exit 0
else
echo "All of the specified args are different"
exit 4
fi
# ./checking.sh
You have provided the following arguments
All of the specified args are equal
You can add set -x in script to troubleshoot the errors.