How can I ignore to follow symbolic links with grep? [duplicate] - unix

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How do you exclude symlinks in a grep?
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Closed 5 years ago.
How can I ignore to follow symbolic links with grep ?
I tried to use with grep -R but it don't help me

Try grep -r instead. It doesn't follow symbolic links .... according to the manual entry!
Another option would be to use find <dir> -P -type f ... | xargs grep .... (Or leave out the -P because not following symlinks is default behavior for find. If you have whitespace in pathnames, use find ... -path0 and xargs -0.)

Related

How do I use grep to find words of specified or unspecified length?

In the Unix command line (CentOS7) I have to use the grep command to find all words with:
At least n characters
At most n characters
Exactly n characters
I have searched the posts here for answers and came up with grep -E '^.{8}' /sample/dir but this only gets me the words with at least 8 characters.
Using the $ at the end returns nothing. For example:
grep -E '^.{8}$' /sample/dir
I would also like to trim the info in /sample/dir so that I only see the specific information. I tried using a pipe:
cut -f1,7 -d: | grep -E '^.{8}' /sample/dir
Depending on the order, this only gets me one or the other, not both.
I only want the usernames at the beginning of each line, not all words in each line for the entire file.
For example, if I want to find userids on my system, these should be the results:
1.
tano-ahsoka
skywalker-a
kenobi-obiwan
ahsoka-t
luke-s
leia-s
ahsoka-t
kenobi-o
grievous
I'm looking for two responses here as I have already figured out number 1.
Numbers 2 and 3 are not working for some reason.
If possible, I'd also like to apply the cut for all three outputs.
Any and all help is appreciated, thank you!
You can run one grep for extracting the words, and another for filtering based on length.
grep -oE '(\w|-)+' file | grep -Ee '^.{8,}$'
grep -oE '(\w|-)+' file | grep -Ee '^.{,8}$'
grep -oE '(\w|-)+' file | grep -Ee '^.{8}$'
Update the pattern based on requirements and maybe use -r and specify a directory instead of a file. Adding -h option may also be needed to prevent the filenames from being printed.
Depending on your implementation of grep, it might work to use:
grep -o -E '\<\w{8}\>' # exactly 8
grep -o -E '\<\w{8,}\>' # 8 or more
grep -o -E '\<\w{,8}\>' # 8 or less

Unix command to find all files [closed]

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I need a unix command to list all files that contains 'foo' in their name ?
We have two commands that do that : grep command and find command !!
what's the best?
Thanks
The find command by itself suffices (unless you want to include files in directories whose name includes "foo"):
find / -type f -name '*foo*'
That checks the leaf name (last part) of the pathnames. If you piped the result of find through grep in a similar way:
find / -type f | grep foo
it would match those files, as well as all files (and directories) inside directories whose name includes "foo".
To filter the list in a more interesting way, you can use grep, which supports regular expressions and other features. For example, you could do
find / -type f | grep -i foo
to match "foo" ignoring case.
But if you want to look at the contents of files, that is grep-specific:
find / -type f -exec grep foo {} +
Further reading:
find
grep
Use find to list all files on the system.
Pair that up with grep to search for a specific file name.
like this:
find / -type f -exec grep -i -r "*foo*" {}

Unix - Using ls with grep

How can I use ls (or other commands) and grep together to search from specific files for a certain word inside that file?
Example I have a file - 201503003_315_file.txt and I have other files in my dir.
I only want to search files that have a file name that contains _315_ and inside that file, search for the word "SAMPLE".
Hope this is clear and thanks in advance for any help.
You can do:
ls * _315_* | xargs grep "SAMPLE"
The first part: ls * _315_* will list only files that have 315 as part of the file name, this list of files is piped to grep which will scan each one of them and look for "SAMPLE"
UPDATE
A bit easier (and actually safer) approach was mentioned by David in the comments bellow:
grep "SAMPLE" *_315_*.txt
The reason why it's safer is that ls doesn't handle well special characters.
Another option, as mentioned by Charles Duffy in the comments below:
printf '%s\0' *_315_* | xargs -0 grep
Change to that directory (using cd dir) and try:
grep SAMPLE *_315_*
If you really MUST use ls AND grep try this:
ls *_315_* | xargs grep SAMPLE
The first example, however, requires less typing...

grep command to search in subdirectories

I have a directory named lists, and have several subdirectories in this named as lists-01, lists-02 and so on.
In every subdirectory, I have a sript called checklist.
I want to use grep command to search for "margin" in each script "checklist", and want to know the particular checklist scripts which contain the word "margin".
I tried using
grep "margin" list*/checklist
but, this is not giving any result.
You can make use of --include to select just the files you want:
grep -Rl --include='*checklist' "margin" .
I am trying to figure out how to include list-0*/ directories, still couldn't find a way.
Note also that your attempt was quite accurate. You only need to add -R for recursive:
grep -R "margin" list-[0-9]*/checklist
How about:
find lists -name checklist -type f -exec grep -H margin {} \;
That says... find, starting in the directory called lists, and all directories below, all files called checklist and look in them for the word margin printing the filename if it is in there.
If you have a modern find, you can replace the \; with + to allow each find to search more than one file and make your query more efficient.
It will search all the files named checklist recursively and then run grep command on those files to find word "margin". -l option will give you only file name and option -w is used for exact match.
find ~/list -type f -name checklist -exec grep -lw "margin" {} +

List only certain files in a directory matching the word BOZO and ending with either '123' or '456'

I'm trying to figure out how to get a list of file names for a file named BOZO but ending with ONLY 123 OR 456.
Files are:
BOZO12389,
BOZOand3
BOZOand456
BOZOand5
BOZOhello123
So the command should only display 'BOZOhello123' and 'BOZOand456'
I can't figure it out. I've tried all forms of LS and GREP that I can think of. The funny thing is, we tried to do it in class for about 10mins and no one could get it (including the instructor).
I did the following and it worked
ls BOZO*456 BOZO*123
Using shell's globs:
ls BOZO*{123,456}
Use regular expressions to help you. The command egrep should help, because it will allow you to use regular expressions.
You're searching for files of the kind BOZO456 and BOZO123
A period . is a wild card, allowing you to substitute for <anything>. The * will let you repeat it 0 or more times. By placing around 123 and 456 round brackets, you will simulate an OR.
Thus, you want any character repeated 0 or more times, followed by 123 or 456.
Example:
egrep "BOZO.*(456|123)" data
Thank you to Nathan Fellman for the help and edits.
You could also use find command :
find . \( -name "BOZO*123" -o -name "BOZO*456" \)
$ ll grep *BOZO* should work too!
This shouldn't be that hard. The most naive way is to ls the directory and then grep for only what you want:
$ ls *BOZO* | grep -e '123$' -e '456$'

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