[Bug 264448] Re: --label should be used with -H too

[Ma Xiaojun]

I guess it is already fixed in 12.04+ (EOL versions ignored)

http://manpages.ubuntu.com/manpages/precise/en/man1/grep.1.html

Correct me if I'm wrong.

** Changed in: grep (Ubuntu)
       Status: New => Fix Released

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https://bugs.launchpad.net/bugs/264448

Title:
  --label should be used with -H too

Status in “grep” package in Ubuntu:
  Fix Released

Bug description:
  Binary package hint: grep

  (Originally reported by Mike Bianchi via Landscape)

  The grep manpage has an example about --label that doesn't work:

  gzip -cd foo.gz | grep --label=foo something

  The above command does not show the "foo" label as expected because
  only one "file" (in this case, stdin) is being grepped.

  In order for it to work, -H (Print the file name for each match) needs
  to be added or else the label will not be printed.

  This can be solved by:
  a) patching grep.c so it automatically adds -H whenever --label is used. This would make the manpage correct. Something like this:
  diff -uNr grep-2.5.3.orig/src/grep.c grep-2.5.3/src/grep.c
  --- grep-2.5.3.orig/src/grep.c	2007-06-28 15:57:19.000000000 -0300
  +++ grep-2.5.3/src/grep.c	2008-09-02 17:51:45.000000000 -0300
  @@ -2137,6 +2137,7 @@

         case LABEL_OPTION:
   	label = optarg;
  +        with_filenames = 1;
   	break;

         case 0:

  b) patching the manpage to fix the example and mention that -H needs to be added. Something like this:
  	"--label  does not imply -H.  If the standard input is the only file
  	read (with either no argument  or  the - argument) and you want
  	matches marked with the --label value, add -H."

  c) do both, i.e., apply the patch and mention in the manpage that -H
  is implied whenever using --label.

  The less impacting change would probably be (b).

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