Category: Bash

Bash has built-in facilities to trim characters at the beginning and end of the value of a variable: $ myvar="AAAthis is a testAAA" $ echo ${myvar##*(A)} this is a testAAA $ echo ${myvar%%*(A)} AAAthis is a test I work as… Read More

To find the files older than 17 days: $ find . -daystart -mtime +17 -print The reason to use `-daystart` is to make things more natural for human beings, because `find` performs some rounding; from the man page: When find… Read More

Code snippet below: myvar=something varname=myvar echo ${!varname} I work as a freelancer, so if you don’t want to do that kind of things yourself or don’t have the time, just drop me a line to hire me.

This can be done using the `ln` command: tempfile=$(mktemp ./lock.XXXXXX) lockfile=./lockfile trap "rm $lockfile" EXIT try=1 while ! ln $tempfile $lockfile > /dev/null 2>&1; do try=$[ $try + 1 ] if [[ $try -gt 10 ]]; then echo "ERROR: Timeout… Read More

Use this: ${THEVAR:+x} Which will expand to “x” if THEVAR is set and not empty. Alternatively, this test can be used: if [[ ! -v THEVAR ]]; then echo "THEVAR is not set" fi But that will work even if… Read More