Piping in bash

[Lingonsylt]

Hi,

I'm sort of ashamed that I have to ask this, as a long-time Linux user, but: why the error message below? (Mountain Lion)

'grep' exists and is in $PATH:

js-MacBook-Pro:~ j$ grep
Usage: grep [OPTION]... PATTERN [FILE]...
Try 'grep --help' for more information.

But I can't pipe through it:

js-MacBook-Pro:~ j$ find . | grep -i jpg
-bash: grep: command not found

Help appreciated!

 

[rhoydotp]

Hi,

I'm sort of ashamed that I have to ask this, as a long-time Linux user, but: why the error message below? (Mountain Lion)

'grep' exists and is in $PATH:

js-MacBook-Pro:~ j$ grep
Usage: grep [OPTION]... PATTERN [FILE]...
Try 'grep --help' for more information.

But I can't pipe through it:

js-MacBook-Pro:~ j$ find . | grep -i jpg
-bash: grep: command not found

Help appreciated!

you should run

find . -type f |grep -i jpg

EDIT: actually, your command worked for me as well. strange

mlmac:~ rhoy$ find . | grep -i jpg | head -2
./Documents/Misc Docs/GBC/concert/Calvary.jpg
./Documents/Misc Docs/GBC/concert/cross.jpg
mlmac:~ rhoy$

 

[balamw]

find . | grep -i jpg

works fine for me?!?

B

 

[Lingonsylt]

Wow, this is so frustrating.. It just seems that sometimes it works, sometimes it doesn't. I haven't been able to figure out the pattern.

However, it seems that I can always manifest the problem by doing this:

1. If Terminal is running, quit it.
2. Open a new Terminal.
3. TYPE (don't use up arrow go retrieve an old command, and don't paste anything) " ls -l . | grep jpg". Again, it's important that you TYPE, NOT PASTE.
4. If you do happen to reproduce the problem by doing (3), if you the press up and edit away the space between the pipe and word "grep", then it *will work*.

It'd be very interesting to know if anyone can reproduce this. Myself.. I'm stumped.

 

[Lingonsylt]

It does seem that, as suggested by rhoydotp, that it always works if I don't put a space between the | and grep (or less, or whatever command I want).

I've been using "<space><pipe>" for 20 years, and it's always worked for me.. And OS X seems to be using bash. I think I know how to work around this problem, but it'd be interesting to learn its cause.

 

[therealseebs]

My guess: You have typed an invisible character, so you have a character that you can't see, but which is not a space and is part of the name, so it's really "Xgrep: command not found" where X is invisible to you.

 

[rhoydotp]

real strange ... this is not an answer but more of a suggestion of what I would have done instead of this pipe

find . -name \*jpg -print

btw, i didn't really suggest anything with the spaces. spaces before/after pipe shouldn't matter, at least in my experience.

 

[Lingonsylt]

therealseebs: I see what you mean with the pasting thing. However, I often see the problem even when not pasting, just typing.

Thanks for the input, guys. I'll work around the problem for now.