I am writing git pre-commit hook to verify the code before it get committed into git. As part of it I need to check the code extension correctly inserted in the code are not, if not I need to auto populate the file extension.

Below is the sample code begin get committed. Here the "@Filetyp" is empty, I need to update it with the file extension 'c'

@header_start
@Titel         : init 
@Filename      : test.c
@Filetyp       :
@Version       : 0001
@Produkt       : xx
@delivery      : xx
@date          : 20160610
@header_end

I tried the below perl one liner to replace the "@Filetyp :" as "@Filetyp :c"

my $ext='c';
qx("perl -p -i -e \"s/(\@Filetyp\\s*?:)/\\1$ext/\" /path/test.c")
[download]

Its get interpretered as below,

perl -p -i -e "s/(@Filetyp\s*?:)/\1c/" /path/test.c
[download]

But I did not get the expected output, it puts the 'c' letter in all the lines, as below

@header_start
@Titel         :c init 
@Filename      :c test.c
@Filetyp       :c
@Version       :c 0001
@Produkt       :c xx
@delivery      :c xx
@date          :c 20160610
@header_end

Pls someone tell me what I am doing wrong here...