bashwhile-loopag

Ag Silver Searcher: output file name when used in while-loop


When using ag (edit: version 0.33.0) in a Bash while loop I can't make it show me any file names:

#!/bin/bash
cat <<__m | while read mod; do ag --nogroup --filename --ignore=local "^use $mod" ./; done
CGI
CGI::Push
__m

Output:

use 4.08;
use 4.08;
...

When executing it directly on the command line it works:

ag --nogroup --filename --ignore=local "^use CGI" ./

Output:

dir/file/ModA.pm:12:use CGI 4.08;
dir/file/ModB.pm:1:use CGI 4.08;

How can I always get the filenames inline?


Solution

  • You could avoid using while read:

    #!/bin/bash
    for mod in CGI CGI::Push ; do
         ag --nogroup --filename --ignore=local "^use $mod" ./
    done
    

    I believe your problem is actually because of a bug(?) in ag. In options.c, it does:

    rv = fstat(fileno(stdin), &statbuf);
    if (rv == 0) {
        if (S_ISFIFO(statbuf.st_mode) || S_ISREG(statbuf.st_mode)) {
            opts.search_stream = 1;
        }
    }
    

    Since you're running under while read, your stdin is not a TTY, so opts.search_stream ends up being set to 1. This causes the opts.print_path to be set to PATH_PRINT_NOTHING. Thus, your paths won't print when run this way. Maybe ag needs an option to forcibly allow this?