Trying to retrieve first 5 characters from string in bash error?
BashShellBash Problem Overview
I'm trying to retrieve the first 5 characters from a string and but keep getting a Bad substitution error for the string manipulation line, I have the following lines in my teststring.sh script:
TESTSTRINGONE="MOTEST"
NEWTESTSTRING=${TESTSTRINGONE:0:5}
echo ${NEWTESTSTRING}
I have went over the syntax many times and cant see what im doing wrong
Thanks
Bash Solutions
Solution 1 - Bash
Depending on your shell, you may be able to use the following syntax:
expr substr $string $position $length
So for your example:
TESTSTRINGONE="MOTEST"
echo `expr substr ${TESTSTRINGONE} 0 5`
Alternatively,
echo 'MOTEST' | cut -c1-5
or
echo 'MOTEST' | awk '{print substr($0,0,5)}'
Solution 2 - Bash
echo 'mystring' |cut -c1-5 is an alternative solution to ur problem.
more on unix cut program
Solution 3 - Bash
Works here:
$ TESTSTRINGONE="MOTEST"
$ NEWTESTSTRING=${TESTSTRINGONE:0:5}
$ echo ${NEWTESTSTRING}
MOTES
What shell are you using?
Solution 4 - Bash
Substrings with ${variablename:0:5} are a bash feature, not available in basic shells. Are you sure you're running this under bash? Check the shebang line (at the beginning of the script), and make sure it's #!/bin/bash, not #!/bin/sh. And make sure you don't run it with the sh command (i.e. sh scriptname), since that overrides the shebang.
Solution 5 - Bash
This might work for you:
printf "%.5s" $TESTSTRINGONE
Solution 6 - Bash
Works in most shells
TESTSTRINGONE="MOTEST"
NEWTESTSTRING=${TESTSTRINGONE%"${TESTSTRINGONE#?????}"}
echo ${NEWTESTSTRING}
# MOTES
Solution 7 - Bash
You were so close! Here is the easiest solution: NEWTESTSTRING=$(echo ${TESTSTRINGONE::5})
So for your example:
$ TESTSTRINGONE="MOTEST"
$ NEWTESTSTRING=$(echo ${TESTSTRINGONE::5})
$ echo $NEWTESTSTRING
MOTES
Solution 8 - Bash
You can try sed if you like -
[jaypal:~/Temp] TESTSTRINGONE="MOTEST"
[jaypal:~/Temp] sed 's/\(.\{5\}\).*/\1/' <<< "$TESTSTRINGONE"
MOTES
Solution 9 - Bash
echo $TESTSTRINGONE|awk '{print substr($0,0,5)}'
Solution 10 - Bash
That parameter expansion should work (what version of bash do you have?)
Here's another approach:
read -n 5 NEWTESTSTRING <<< "$TESTSTRINGONE"
Solution 11 - Bash
The original syntax will work with BASH but not with DASH. On debian systems you might think you are using bash, but maybe dash instead. If /bin/dash/exist then try temporarily renaming dash to something like no.dash, and then create soft a link, aka ln -s /bin/bash /bin/dash and see if that fixes the problem.