[SOLVED] grep, recursive

pan64 · 03-09-2019, 02:30 AM

Quote:

Originally Posted by bkelly

I don't agree with that.

Unfortunately it is irrelevant. This is how it is working. I know you wanted something else, but grep can't read your mind (and even my mind).

Quote:

Originally Posted by bkelly

By specifying a file limitation, such as *.cpp

You can't specify a file limitation. As it was already explained, *.cpp will be expanded by the shell before executing grep, so instead of *.cpp a list of files will be passed to grep. You can check it if you execute set -xv before this grep command.

Quote:

Originally Posted by bkelly

As noted, and as I read the man page, it should work.

Unfortunately the command line parsing/evauluation is not part of grep (or any other command), it is made by the shell. This is some kind of preprocessing occurred unconditionally before the real execution. In windows this works differently.
To achieve what you need you need to implement something, because there is no such tool available (installed) by default. An example was already posted by smallpond.

ehartman · 03-09-2019, 04:44 AM

Quote:

Originally Posted by smallpond

This is defined in my .bashrc for doing recursive grep. Maybe others have something better:

Code:

gfind () 
{ 
    if [ -z "$1" ]; then
        return;
    fi;
    find . -type f -exec grep -H "$1" \{} \; 2> /dev/null
}

You don't need the return, it can be simplified to

Code:

gfind()
{ 
   if [ "$1" ]; then
      find . -type f -exec grep -H "$1" \{} \; 2> /dev/null
   fi
}

and you could even extend it with a 2nd argument for the filenames you're doing the grep on

Code:

gfind()
{
   test "$2" && FILES="-name $2"
   if [ "$1" ]; then
      find . -type f "FILES" -exec grep -H "$1" \{} \; 2> /dev/null
   fi
}

ondoho · 03-10-2019, 06:45 AM

Quote:

Originally Posted by ehartman

The thing is that "*.cpp" is evaluated BY the shell in the current directory only, before grep gets passed the commandline.
So grep will search recursively for the .cpp files that have the same name as the ones IN that current directory (no others).
As you went one dir upwards there were no .cpp files in that directory thus grep didn't have any filenames to search for.

as i already noted in post #10, but you said it better.
relevant information tends to get lost when op is too keen on complaining.