grep version is 2.10, and it does not respond anything, even on a small set of small files, while the same line on another Ubuntu machine works fine where grep version is 2.16...

The command is:

grep -r "myVariable"

Instead of returning nothing, or some file names and lines, like this:

path/to/file.c:     myVariable++;
path/to/file2.c:    int myVariable;

The command shell stays busy and I have to halt it using ctrl+C

What is the problem or how do I investigate it?

  • 2
    Without specifying, what's the command how can you expect someone to help you?
    – user495867
    Jan 4, 2017 at 13:36
  • the command is in the title, Ok I'll edit Jan 4, 2017 at 13:40
  • And of course pattern occurs there. Jan 4, 2017 at 13:44
  • 1
    You should specify which file(s) to search for the pattern. You can use wild cards or a single file, for example grep "alias" ~/.bashrc should produce a few lines of output (there are some aliases in the default .bashrc).
    – sudodus
    Jan 4, 2017 at 13:49
  • This means that the 2.10 version of grep does not support this feature.
    – Pilot6
    Jan 4, 2017 at 13:50

2 Answers 2


Since you don't specify any input file, grep waits for you to provide input data on its standard input.

The behavior where -r will use the current directory by default is non-standard (in fact, -r itself is), and was introduced in GNU grep 2.11.

  • No path, just: (standard input): Jun 14, 2018 at 6:50

I think you are missing file name. From the grep's man page the syntax should be as below :


Ex : grep -r pattern your_directory_path
  • I am using grep (GNU grep) 2.16. It doesn't work for me if I don't specify a file name. Jan 4, 2017 at 14:00

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