When I run this script:
#!/bin/bash
if [[ "abcd" =~ ^.*$ ]]; then
echo "something"
fi
I get:
./tmp2.sh: line 3: conditional binary operator expected
./tmp2.sh: line 3: syntax error near `=~'
./tmp2.sh: line 3: `if [[ "abcd" =~ ^.*$ ]]; then'
I've tried all suggestions I've found, but still the same:/ Help me, please!
Given that you're seeing a bash-specific error message, we can rule out that something other than bash is running the script (if it were a POSIX-features-only shell, such as sh on some systems, you'd instead see an error message relating to [[).
The most likely explanation:
bash version is < 3.0, and therefore doesn't support the =~ operator.
echo $BASH_VERSION in your script.The specific error you're seeing is bash's way of saying: "I'm seeing a string I don't recognize as an operator."
Run your script with bash script.sh not sh script.sh. It probably would also work with ./script.sh if script.sh is already executable since you're using the header #!/bin/bash.
this should work
re='^.*$'
if [[ "abcd" =~ $re ]]; then
echo "something"
fi
=~ syntax works in all versions of Bash starting 3.0.
\ -prefixed sequences such as \< or \s), this is NOT the problem here - yours an the OP's code are equivalent.This is almost identical to the error you get in all versions of bash that support regex if you put ~= rather than =~.
bash, not some other shell orbashin POSIX mode?