Is it acceptable to use `grep` to check for the presence of a string in a file within an init script?

Question

Is it okay for me to check the contents of a file for a given string with grep in an init script?

I am concerned about introducing dependencies and general convention when it comes init scripts, and if running grep or other tools violates some credo.

supposedly you're supposed to use $() versus \`backticks\` now, but other than that I think you're good. Then again, backticks are more universal though ?deprecated?. Even the most stripped down versions of linux and linuxy OSs have grep. — MattPark, May 15 '13 at 19:47
When I can do $(string expansion) on stackexchange, then I'll stop using `backticks`. :) — mbrownnyc, May 16 '13 at 13:11

score 6 · Accepted Answer · answered May 15 '13 at 18:47

6

iniscripts can do whatever they want. Of course it makes sense not to introduce new dependencies, just for the initscripts. grep however is fine on pretty much any system that's posix/susv3 compatible (linux, bsd, solaris, other derivatives).

For more utilities that should always be there, see http://pubs.opengroup.org/onlinepubs/009695399/idx/utilities.html

answered May 15 '13 at 18:47

Dennis Kaarsemaker

18,793
2
43
69

Surprised that `which` isn't on there, but I guess that can be done in in with a shell one-liner. – mbrownnyc May 16 '13 at 13:13
2

You can use `type` instead of which. The functionality is slightly different, but you can get equivalent results. – Dennis Kaarsemaker May 16 '13 at 13:27

score 1 · Answer 2 · edited May 15 '13 at 20:12

1

In short, YES. So long as the file you are looking for is mounted at that point.

edited May 15 '13 at 20:12

Magellan

4,431
3
29
53

answered May 15 '13 at 18:44

mdpc

11,698
28
51
65

I wasn't really asking if it was _possible_, but I will in fact handle this condition as well, so thanks. – mbrownnyc May 15 '13 at 19:21
1

It IS acceptable and you will find that many of the init scripts do this. – mdpc May 15 '13 at 19:27

Is it acceptable to use `grep` to check for the presence of a string in a file within an init script?

2 Answers2