Grep From Files and Display the File Name On Linux or Unix System

How do I grep from a number of files and display the file name only? How do I force the grep command to display the filename before the matching lines in its output?

When there is more than one file to search it will display file name by default. Consider the following grep command:

How to display filename before matching line in grep

By default grep display filename if you provide multiple filenames. For example:
grep 'foo' file1 file2 grep '192.168.2.254' /etc/hosts /etc/resolv.conf grep -n '192.168.2.254' /etc/hosts /etc/resolv.conf

#################################################### ## Always show filename headers with output lines.## ## Works with BSD/macOS/GNU/Linux grep version ## #################################################### grep -H 'search-word' filename1 filename2 grep '192.168.2.254' /etc/hosts /dev/null ########################## ### gnu/Linux grep only ## ########################## grep --with-filename 'foo' file1 file2 grep --with-filename '192.168.2.253' /etc/{hosts,resolv.conf}

Linux grep display filename before matching line

grep show filename before matching line

In this example, I need to search for ‘http://www.cyberciti.biz’ in all files and display matched filenames only, run:
grep -l -R 'http://www.cyberciti.biz'
Now replace all occurrences of ‘http://www.cyberciti.biz’ with ‘https://www.cyberciti.biz’ using the sed command:

## get filenames ##
files=$(grep -l -R 'http://www.cyberciti.biz' . )
echo "$files"
## replace using sed ##
for f in $files
do
   sed -i 's+http://www.cyberciti.biz+https://www.cyberciti.biz+g' "$f"
done

Conclusion – Grep from files and display the file name

Let us summaries all the grep command option in Linux or Unix:

grep -l 'word' file1 file2 : Display the file name on Linux and Unix instead of normal output
grep -L 'string' file1 file2 : Suppress normal output and show filenames from which no output would normally have been printed
grep -n 'string' filename : Force grep to add prefix each line of output with the line number within its input file
grep --with-filename 'word' file OR grep -H 'bar' file1 file2 file3: Print the file name for each match

This entry is 5 of 7 in the Linux / UNIX grep Command Tutorial series. Keep reading the rest of the series:

How To Use grep Command In Linux / UNIX
Regular Expressions In grep
Search Multiple Words / String Pattern Using grep Command
Grep Count Lines If a String / Word Matches
Grep From Files and Display the File Name
How To Find Files by Content Under UNIX
grep command: View Only Configuration File Directives

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin, DevOps engineer, and a trainer for the Linux operating system/Unix shell scripting. Get the latest tutorials on SysAdmin, Linux/Unix and open source topics via RSS/XML feed or weekly email newsletter.

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13 comment

for i in `ls` ; do
grep -q “whatever” $i && echo $i
done

nixCraft says:
October 1, 2010 at 5:42 am
Why ls? It will fail when you have file names with white spaces. A better way is to use wild cards:
```
for i in * ; do
grep -q â€œwhateverâ€ $i && echo $i
done
```
1. lUser says:
  February 20, 2011 at 8:19 pm
  what about
  grep -rI â€œwhateverâ€ ./ | cut -d: -f1 | sort -u
  nb it will fail on file containing “:” such as some perl man pages but…
  …Or just add some proper form
  for i in `ls` ; do
  grep -q â€œwhateverâ€ “$i” && echo “$i”
  done

or if you need to search all file and subdirs within a dir you can run the commands above. Just replace `ls` with `find . -type f`.

Or better yet, use xargs.
find . -type f | xargs grep html

If you want to deal with spaces etc…
find . -type f | xargs -I {} grep -H foo "{}"

yoander (sedlav) says:
October 13, 2010 at 5:36 pm
Dealing with space with a shorter form
find . -type f -print0 | xargs -0 grep foo

I agree, find is working great for me.

find -name *.log -uid 1000

You can find files only owned by uid. Nifty feature.

How do I grep if i am looking for a specfic percentage?
grep -w “68%-100% /usr/local/stage”

thanks in advance

ls | while read FILE; do echo “$FILE” done;

This handles whitespace and other nasties nicely.

how can i grep
CA
from filename AUZ_CA_EL.txt

BrianBlaze says:
November 27, 2012 at 5:09 pm
cat AUZ_CA_EL.txt | grep “CA”

how do I know the location and file name form the result that grep shows?
I use command like cat * | grep
Now what I need is the location of the file name along withe the grep result.

Help anyone

THX for the “$FILE” solution! Worther than 100 webpages!

Josh Keife says:
September 30, 2010 at 5:35 pm
for i in `ls` ; do
grep -q “whatever” $i && echo $i
done
1. nixCraft says:
  October 1, 2010 at 5:42 am
  Why ls? It will fail when you have file names with white spaces. A better way is to use wild cards:
```
for i in * ; do
grep -q â€œwhateverâ€ $i && echo $i
done
```
  1. lUser says:
    February 20, 2011 at 8:19 pm
    what about
    grep -rI â€œwhateverâ€ ./ | cut -d: -f1 | sort -u
    nb it will fail on file containing “:” such as some perl man pages but…
    …Or just add some proper form
    for i in `ls` ; do
    grep -q â€œwhateverâ€ “$i” && echo “$i”
    done
Josh Keife says:
September 30, 2010 at 5:41 pm
or if you need to search all file and subdirs within a dir you can run the commands above. Just replace `ls` with `find . -type f`.
mlathe says:
October 2, 2010 at 12:45 am
Or better yet, use xargs.
find . -type f | xargs grep html
If you want to deal with spaces etc…
find . -type f | xargs -I {} grep -H foo "{}"
1. yoander (sedlav) says:
  October 13, 2010 at 5:36 pm
  Dealing with space with a shorter form
  find . -type f -print0 | xargs -0 grep foo
layman says:
October 19, 2010 at 7:46 am
I agree, find is working great for me.
find -name *.log -uid 1000
You can find files only owned by uid. Nifty feature.
Becky Gawat says:
March 19, 2012 at 6:55 pm
How do I grep if i am looking for a specfic percentage?
grep -w “68%-100% /usr/local/stage”
thanks in advance
willywonker says:
May 3, 2012 at 8:44 pm
ls | while read FILE; do echo “$FILE” done;
This handles whitespace and other nasties nicely.
avinash says:
June 7, 2012 at 5:22 pm
how can i grep
CA
from filename AUZ_CA_EL.txt
1. BrianBlaze says:
  November 27, 2012 at 5:09 pm
  cat AUZ_CA_EL.txt | grep “CA”
Ã–zzesh says:
December 5, 2012 at 7:45 am
how do I know the location and file name form the result that grep shows?
I use command like cat * | grep
Now what I need is the location of the file name along withe the grep result.
Help anyone
a says:
January 11, 2014 at 10:54 pm
THX for the “$FILE” solution! Worther than 100 webpages!

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nixCraft