BASH – grep – works on command line, but not script

bash-scripting

I am trying to get the number of occurrences in a script and when running the command on the command line, it works fine, but not in a script. Both variables are initialized. FILE_PATH is the absolute path of the file and VARIABLE_NAME is something like firstName or lastName.

VARIABLE_NAME="_firstName"    
grep -cP "\(this\.|\s\){1}$VARIABLE_NAME" $FILE_PATH

When I take $VARIABLE_NAME out of the script and replace it directly with what I am looking for, it works as expected, so it is something with the replacement.

Any ideas what I can try?

Best Answer

The problem seems to reside in your regex. can you show us what you are trying to match?

if you are trying to match constructs like this : 

this.contentOfVar
  contentOfVar

try it with the following :

grep -cP "(this\.|\s)$VARIABLE_NAME" $FILE_PATH

This works in GNU grep. You don't have to specify {1}, since the default will be 1. With the -P flag on, \( and \) will match literal parenthesis in the string, since this is the perl behavior.

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