If you want to use Linux, learning the common utilities or commands will go a long way. However, we recommend utilizing the command-line interface (CLI) because it’s quicker and offers more control. Tasks that require multiple steps on the GUI can be done in a matter of seconds by entering commands into the CLI.
Find Command
find command is used to search and locate les or directories that meet certain conditions.
# finds passwd.txt file under /home and deep
find /home -name passwd.txt
# finds passwd.txt file ignoring case under /home and deep
find /home -iname passwd.txt
# finds all Java files from current dir and deep
find . -type f -name “*.java”
# finds all files
find / -type f -perm 0777
# finds all executable files
find / -perm /a=x
# finds all files that belong to asotobu
find /home -user asotobu
# finds all files that belong to the developer group
find /home -group developer
# finds all files modified in the last 10 days
find / -mtime 10
# finds all files accessed in the last 10 minutes
find / -amin -10
More Command
more command lets you view output in a scrollable manner for example.
more /etc/passwd
ls -ll | more
- Up arrow and Down arrow let you scroll through the output.
- Space key scrolls down one page.
- b key scrolls up one page.
- / search in the text.
Sed Command
sed is used among other things to apply substitution, nd or replace les content.
# changes the first occurrence in each line containing the blue word to red
sed ‘s/blue/red/’ items.txt
# changes the second occurrence in each line containing the blue word to red
sed ‘s/blue/red/2’ items.txt
# changes all the occurrences containing the blue word to red
sed ‘s/blue/red/g’ items.txt
# changes all the occurrences from line number 1 to 3 containing the blue word to red
sed ‘1,3 s/blue/red/g’ items.txt
# deletes line number 5
sed ‘5d’ items.txt
# deletes from line 12 to last line
sed ’12,$d’ items.txt
The sed command also supports regular expression.
AWK
awk is a text manipulation tool implementing a powerful scriptin
