Help with grep

[ɹəuəllıʍ ʇɐb]

This is a Unix question, actually, but grep may also exist on Linux. And I know that there are some knowledgeable Unix people around here anyway.

I need to search a large directory for occurrences of a string that looks something like that

some_thing[0]

I tried it like that, and it didn't find anything.

grep some_thing[0] *

Same if I put the expression in quotes or double-quotes.

This, however, finds hundreds of instances

grep some_thing *

So how do I search for things with certain special characters?

[korgg]

My collegue came up with this:

grep -e "thing_to_find" -R /some_dir/where/the/search/starts

Might wanna look at the man at the arguments if this is not working .. No linux machine around here :( ...

My way was way too long to put in here :D ...

[ɹəuəllıʍ ʇɐb]

Thanks for the reply. Unfortunately it makes no difference. With or without the -e parameter, "thing_to_find" works ok, but "thing_to_find[0]" doesn't find anything.

[trackrat]

This may help you.

http://pegasus.rutgers.edu/~elflord/unix/grep.html

[scuzzman]

You'll probably want something like this:

grep some_thing\[0\] *

The backslashes (\) escape the brackets as they are parsed in the regular expression. For more information on regular expressions, check out this tutorial: http://www.gnoppix.org/pages/rute/node8.html

And yes, grep exists on most every *nix implementation including Linux and *BSD.

[Topband]

I'm not sure if this is of any help, I've copied the help file from my grep.

Usage: grep [OPTION]... PATTERN [FILE] ...

Search for PATTERN in each FILE or standard input.

Example: grep -i 'hello world' menu.h main.c

Regexp selection and interpretation:

-E, --extended-regexp PATTERN is an extended regular expression

-F, --fixed-strings PATTERN is a set of newline-separated strings

-G, --basic-regexp PATTERN is a basic regular expression

-P, --perl-regexp PATTERN is a Perl regular expression

-e, --regexp=PATTERN use PATTERN as a regular expression

-f, --file=FILE obtain PATTERN from FILE

-i, --ignore-case ignore case distinctions

-w, --word-regexp force PATTERN to match only whole words

-x, --line-regexp force PATTERN to match only whole lines

-z, --null-data a data line ends in 0 byte, not newline

Miscellaneous:

-s, --no-messages suppress error messages

-v, --invert-match select non-matching lines

-V, --version print version information and exit

--help display this help and exit

--mmap use memory-mapped input if possible

Output control:

-m, --max-count=NUM stop after NUM matches

-b, --byte-offset print the byte offset with output lines

-n, --line-number print line number with output lines

--line-buffered flush output on every line

-H, --with-filename print the filename for each match

-h, --no-filename suppress the prefixing filename on output

--label=LABEL print LABEL as filename for standard input

-o, --only-matching show only the part of a line matching PATTERN

-q, --quiet, --silent suppress all normal output

--binary-files=TYPE assume that binary files are TYPE

TYPE is 'binary', 'text', or 'without-match'

-a, --text equivalent to --binary-files=text

-I equivalent to --binary-files=without-match

-d, --directories=ACTION how to handle directories

ACTION is 'read', 'recurse', or 'skip'

-D, --devices=ACTION how to handle devices, FIFOs and sockets

ACTION is 'read' or 'skip'

-R, -r, --recursive equivalent to --directories=recurse

--include=PATTERN files that match PATTERN will be examined

--exclude=PATTERN files that match PATTERN will be skipped.

--exclude-from=FILE files that match PATTERN in FILE will be skipped.

-L, --files-without-match only print FILE names containing no match

-l, --files-with-matches only print FILE names containing matches

-c, --count only print a count of matching lines per FILE

-Z, --null print 0 byte after FILE name

Context control:

-B, --before-context=NUM print NUM lines of leading context

-A, --after-context=NUM print NUM lines of trailing context

-C, --context=NUM print NUM lines of output context

-NUM same as --context=NUM

--color[=WHEN],

--colour[=WHEN] use markers to distinguish the matching string

WHEN may be `always', `never' or `auto'.

-U, --binary do not strip CR characters at EOL (MSDOS)

-u, --unix-byte-offsets report offsets as if CRs were not there (MSDOS)

`egrep' means `grep -E'. `fgrep' means `grep -F'.

With no FILE, or when FILE is -, read standard input. If less than

two FILEs given, assume -h. Exit status is 0 if match, 1 if no match,

and 2 if trouble.

[ɹəuəllıʍ ʇɐb]

Thanks to all who responded :flowers:

The escape character did the trick, but the reg-ex link also revealed fgrep to me, which matches strings instead of reg-exes.　Had I read the man pages more carefully, I would also have found the -F parameter on the standard grep.

For years and years I couldn't use grep correctly, mainly because I didn't understand the concept of regular expressions. Now I finally do :D

Thanks again, everyone!

[ɹəuəllıʍ ʇɐb]

1½ years later I have another problem with grep/fgrep. I have circumvented it by downloading everything to Windows, then do a Windows search on it. However, if I need a similar search another time, I would be happy to avoid the large downloads.

My problem: I needed to find the negative number six in a large directory: -6. fgrep just says 'Illegal option -6'.

I tried fgrep -6 *

I tried fgrep "-6" *

I tried fgrep \-6 *

Nothing works...

[Seshomaru Samma]

If value is ascii

should be something like:

grep -r -- -6 name_of_directory

in Debian Linux that is......

should be the same in Unix

[jason.b.c]

What "Unix" system are we talking about here anyways...?

FreeBsd..? or one of the Bsd's..

[ɹəuəllıʍ ʇɐb]

If value is ascii

should be something like:

grep -r -- -6 name_of_directory

in Debian Linux that is......

should be the same in Unix

Thanks; but sorry - it lists the -r option as invalid.

What "Unix" system are we talking about here anyways...?

FreeBsd..? or one of the Bsd's..

HP-UX.

P.S. I just tried without the -r option (but with -- whatever that means) and that returned the correct result. Thanks

[Seshomaru Samma]

from the man file:

-R, -r, --recursive equivalent to --directories=recurse

--include=PATTERN files that match PATTERN will be examined

In Linux you need the -r option to look in all files in a directory , but maybe Unix is different.....

what does your man file say?

man grep

[jason.b.c]

shouldn't that be..

man | grep

..?

[ɹəuəllıʍ ʇɐb]

man grep gives a very long output, but there is no -r option.

[jason.b.c]

man grep gives a very long output, but there is no -r option.

well i guess that if it isn't there then it isn't there...

@Pat

if you are trying to search for a particular file in a directory then why are you not trying the "locate" or "find" commands..?

[Seshomaru Samma]

grep allows you to search inside a file

i googled the HPUX man files and it seems to be somewhat different than the Debian one, not as many options.