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c/nostupidquestions · by sighofannoyance@lemmy.world · 2y

How do I "ls -R | cat | grep print" ?

Hi friends! 🤓 I am on a gnulinux and trying to list all files in the active directory and it's subdirectories. I then want to pipe the output to "cat". I want to pipe the output from cat into grep.

Please help! 😅

32 points · 23 comments · view on lemmy.world

23 Comments

geekworking@lemmy.world · 23 pts · 2y (2 replies)

Use find instead.

caseyweederman@lemmy.ca · 5 pts · 2y

Seconded, but I always have to look up the syntax. --type=file --name="string"?

sighofannoyance@lemmy.world · 2 pts · 2y

Thank you! 🤩

JTskulk@lemmy.world · 17 pts · 2y (1 reply)

Bro you can just run find

sighofannoyance@lemmy.world · 4 pts · 2y

thanks dude

bjoern_tantau@swg-empire.de · 16 pts · 2y (5 replies)

Note, you almost never have to use cat. Just leaving it out would have been enough to find your file (although find is still better).

When you want to find a string in a file it's also enough to use grep string file instead of cat file | grep string. You can even search through multiple files with grep string file1 file2 file* and grep will tell you in which file the string was found.

litchralee@sh.itjust.works · 13 pts · 2y (1 reply)

Obligatory link to the Useless Use of Cat Awards

FuglyDuck@lemmy.world · 3 pts · 2y

for a moment, I thought OP was looking for cat photos or something.

sighofannoyance@lemmy.world · 4 pts · 2y (2 replies)

So I could use something like grep string -R * to find any occurrence of the string in any files in the folder and sub-folders.

thank you!

JoeyJoeJoeJr@lemmy.ml · 6 pts · 2y (1 reply)

grep -r string .

The flag should go before the pattern.

-r to search recursively, . refers to the current directory.

Why use . instead of *? Because on it's own, * will (typically) not match hidden files. See the last paragraph of the 'Origin' section of: https://en.m.wikipedia.org/wiki/Glob_(programming). Technically your ls command (lacking the -a) flag would also skip hidden files, but since your comment mentions finding the string in 'any files,' I figured hidden files should also be covered (the find commands listed would also find the hidden files).

EDIT: Should have mentioned that -R is also recursive, but will follow symlinks, where -r will ignore them.

notfromhere@lemmy.ml · 2 pts · 2y

TIL

Shadow@lemmy.ca · 15 pts · 2y (2 replies)

To answer your og question since it is a valuable tool to know about, xargs.

ls | xargs cat | grep print

Should do what you want. Unless your file names have spaces, then you should probably not use this.

018118055@sopuli.xyz · 6 pts · 2y

find -print0 | xargs -0 can handle spaces

Edit and you probably want xargs --exec instead of piping after

sighofannoyance@lemmy.world · 4 pts · 2y

thank you

shrugal@lemm.ee · 5 pts · 2y (1 reply)

I think you can just do grep print **/*.

sighofannoyance@lemmy.world · 1 pts · 2y

ty

surewhynotlem@lemmy.world · 4 pts · 2y (1 reply)

It's valuable to learn how to do an inline loop

ls | while read A; do cat $A | grep print; done

This will read each line of ls into variable A, then it'll get and grep each one.

sighofannoyance@lemmy.world · 1 pts · 2y

thank you

muix@lemmy.sdf.org · 3 pts · 2y

ripgrep does exactly what you want

visnae@lemmy.world · 2 pts · 2y (1 reply)

grep -r print .

I.e. Grep on print recursively from . (current directory)

Or for more advance search find . -name "*.sh" -exec grep -H print {} \;

I.e find all files with sh extension and run grep on it ({} become the filename). -H to include filename in output.

sighofannoyance@lemmy.world · 1 pts · 2y

this is great ty!

notfromhere@lemmy.ml · 2 pts · 2y (1 reply)
[ removed ]
sighofannoyance@lemmy.world · 1 pts · 2y

ty

Toes@ani.social · 2 pts · 2y

I just pipe to more and filter with /