Question

for example qa_sharutils-2009-04-22-15-20-39, want chop last 20 bytes, and get ‘qa_sharutils‘.

I know how to do it in sed, but why $A=${A/.\{20\}$/} does not work?

Thanks!

Answer 1

If your string is stored in a variable called $str, then this will get you give you the substring without the last 20 digits in bash

${str:0:${#str} - 20}

basically, string slicing can be done using

${[variableName]:[startIndex]:[length]}

and the length of a string is

${#[variableName]}

EDIT:
solution using sed that works on files:

sed 's/.\{20\}$//' < inputFile