1. Introduction
In this article, we will see how the find -exec Linux command is used. Find command is used -exec argument in Linux to find the files with different extensions in the directories.
2. Linux Find command and exec option
Find command in Linux has expression and action. The expression part is the first one that is used for filtering the files selected. Action is to act upon the filtered one.
2.1 Prerequisites
You need Linux or macOS or windows environment with bash shell.
2.2 Download
On windows, you can download Unix emulator like cygwin.
2.3 Find Command
Find command can be used to find in a directory the files with an extension. Below is the sample to search for .wav in the Audio directory.
Find files with extension
~ bhagvan.kommadi$ find Audio/ -name *.wav Audio//amy.wav
you can also add -exec flag to act on the filtered files. Below is the sample.
Find -exec
~ bhagvan.kommadi$ find Audio/ -name *.wav -exec file {} \;
Audio//amy.wav: RIFF (little-endian) data, WAVE audio, Microsoft PCM, 16 bit, stereo 44100 Hz
2.4 The -exec expression
In Linux, -exec expression has a command, placeholder, and command delimiter. Delimiters can be ; (semi-colon) and + (plus sign). the semicolon is used to repeat each filtered file separately. plus sign is used to concatenate the filtered files.
2.5 Custom function example
You can have a custom function written which can be executed through the -exec option. Below is the example.
Custom Function
~ bhagvan.kommadi$ do hello () { echo "Doing with $1";}
~ bhagvan.kommadi$ export -f dohello
~ bhagvan.kommadi$ find . -exec bash -c 'dohello "$0"' {} \;
Doing with .
Doing with ./.mlnet
Doing with ./.mlnet/log.txt
Doing with ./.eclipse
Doing with ./.eclipse/240486851_macosx_cocoa_x86_64
Doing with ./.eclipse/240486851_macosx_cocoa_x86_64/configuration
Doing with ./.eclipse/240486851_macosx_cocoa_x86_64/configuration/org.eclipse.update
Doing with ./.eclipse/240486851_macosx_cocoa_x86_64/configuration/org.eclipse.update/platform.xml
Doing with ./.eclipse/240486851_macosx_cocoa_x86_64/configuration/org.eclipse.core.runtime
Doing with ./.eclipse/240486851_macosx_cocoa_x86_64/configuration/org.eclipse.core.runtime/.mainData.1
2.6 The Results Placeholder
The results placeholder is represented by two curly braces {}. Below is the example where place holder for results is used at multiple places.
Results Placeholder
~ bhagvan.kommadi$ find . -name "*.wav" -exec bash -c "basename \"{}\" && file \"{}\" | awk -F: '{\$1=\"\"; print \$0 }'" \;
voice 4.wav
RIFF (little-endian) data, WAVE audio, Microsoft PCM, 16 bit, mono 8000 Hz
voice 5.wav
RIFF (little-endian) data, WAVE audio, Microsoft PCM, 16 bit, mono 16000 Hz
voice 2.wav
RIFF (little-endian) data, WAVE audio, Microsoft PCM, 16 bit, mono 16000 Hz
us2.wav
RIFF (little-endian) data, WAVE audio, Microsoft PCM, 16 bit, mono 16000 Hz
voice 3.wav
RIFF (little-endian) data, WAVE audio, Microsoft PCM, 16 bit, mono 16000 Hz
2020-02-04_13-27-54.wav
RIFF (little-endian) data, WAVE audio, stereo 44100 Hz
voice 1.wav
2.7 The Delimiter.
Below is the example for delimiter in find -exec command and option.
Delimiter
~ bhagvan.kommadi$ find . -name "*.mp3" -exec echo {} \;
./Music/Music/Media.localized/Music/AcousticSheep, LLC/Unknown Album/01 Noise_Sleep_Induction.mp3
./Music/Music/Media.localized/Music/AcousticSheep, LLC/Ginarator/01 Pentatonic Waves.mp3
./Music/Music/Media.localized/Music/AcousticSheep, LLC/Ginarator/02 a minor thing.mp3
./Music/Music/Media.localized/Music/Unknown Artist/Unknown Album/ToDreamsUnsettled.mp3
2.8 Summary
We looked at the Linux command find with -exec option. Find command is highly used for search the files based on condition passed through exec expression. It can be used for a deep search in a directory hierarchy.
3. Download the Source Code
You can download the full source code of this example here: How do we use find -exec?
