Use bash to remove symbols from text file - regex

Question

I have a bunch of txt-files containing stuff like this:
text_i_need_to_remove{text_i_need_to_retain}
text_i need_to_remove{text_i_need_to_retain}
...
How do I remove text before curly braces (and curly braces themselves) and retain just only text_i_need_to_retain?

Answer 1

Deleting everything upto { or } at end of line
:%s/.*{\|}$//g
From bash shell, you can use text processing tools like sed and awk. Assume file is named ip.txt
1) With sed, which is pretty similar to regex we used inside vim. The -i flag allows to make change in place, i.e it modifies the input file itself.
$ sed -i 's/.*{\|}$//g' ip.txt
2) With awk, one can again use substitution or in this case, split the line on curly brackets and use only the second column.
$ awk -F'{|}' '{print $2}' ip.txt > tmp && mv tmp ip.txt
If you have GNU awk, there is -i inplace option for in place editing
$ gawk -i inplace -F'{|}' '{print $2}' ip.txt
To make changed to all files in current directory, use
sed -i 's/.*{\|}$//g' *
Or if they have common extension, say .txt, use
sed -i 's/.*{\|}$//g' *.txt

Answer 2

:%s/^.*{\(.*\)}$/\1/ or in bash, sed 's/^.*{\(.*\)}$/\1/ foo.txt
\(.*\) is a control group which feeds into \1 and looks like a lumbering zombie.

Answer 3

you can use this in vim;
:%s/^.*{// | %s/}$//
you can also use this script; first run this, if everythink is ok, uncomment sed with -i option as below;
#!/bin/bash
for item in $(ls /dir/where/my/files/are)
do
sed -i 's/^.*{//;s/}$//' /dir/where/my/files/are/$item
done
sed -i ; inplace replace
or
Only use as below;
sed -i 's/^.*{//;s/}$//' /dir/where/my/files/are/*

Answer 4

Perl can be used to do the substitution on all files:
perl -i -pe 's/.*{|}$//g' *.txt