Terminal commands

terminal
Published

June 2, 2020

Search by Type (file or dir)

  • find . | Find all the files & directories under current directory

  • find <dir> | Find all the files & directories under

  • find <dir> -type d | Find only directories under specific directory

  • find . -type d | Find only directories under current directory

  • find <dir> -type f | Find only files under specific directory

  • find . -type f | Find only files under current directory

Search by file name

  • find <dir> -type f -name "<test1.txt>" | Find a file with a specific name
  • find <dir> -type f -name "<test*>" | Find a file starting with the name ‘test’
  • find <dir> -type f -iname "<test*>" | Find a file starting with the name ‘test’ or ‘Test’ & Case Insensitive
  • find <dir> -type f -iname "<*.py>" | Find a file ending with the name ‘.py’ & Case Insensitive

Search by time / day

  • find <dir> -type f -mmin -10 | All the files modified in last 10 mins

  • find <dir> -type f -mmin +10 | All the files modified in more than last 10 mins ago

  • find <dir> -type f -mmin +1 -mmin -5 | More than 1 min ago and less than 5 mins ago

  • find <dir> -type f -mtime -20 | Files modified less than 20 days ago

    • mmin, mtime
    • amin, atime
    • cmin, ctime

Search by file size

  • find <dir> -size +5M | Find all the files over 5 MB under

    directory

    • M - MB
    • k - KB
    • G - GB

  • ls -lah <dir> | List all files and dirs with size in MB

  • find <dir> -empty | Find all empty files in

    directory

Search based on permissions

  • find <dir> -perm 777
##### Change user & group for every file & dir under
  • -exec | Executes the following command on the results from preceding command
  • {} | Placeholder for just the filenamees that would be be used in case of chown command
  • + or \; | Either can be used to end the command
  • find <dir> -exec chown [user]:[group] {} +
Lets try setting permissions of all directories to 775 and all files to 664
  • find <dir> -type d -exec chmod 775 {} +
  • find <dir> -type f -exec chmod 664 {} +

Search and perform actions

  • find <dir> -type f -name "*.jpg" | Search all image files ending in .jpg in and subsequent directories
  • find <dir> -type f -name "*.jpg" -maxdepth 1 | Search all image files ending in .jpg only and only in
  • find <dir> -type f -name "*.jpg" -exec rm {} + | Deletes all the files returned from the command precesing -exec
  • find <dir> -type f -name "*.jpg" -maxdepth 1 -exec rm {} + | Deletes all the files returned from the command precesing -exec

_grep (Global Regular Expression Print)

  • grep is case sensitive

Finding is a given text is present in some file

  • grep "text_to_find" <file_name> | Searching for some text in a normal file
  • grep -w "text_to_find" <file_name> | Return results from file_name only when whole words match text_to_find
  • grep -wi "text_to_find" <file_name> | Returns results with both lower case and upper case with text_to_find

Finding some additional information

Line number of where we found our match
  1. Returns results with line number.
  • grep -win "text_to_find" <file_name> | Returns results with line numbers in file_name
  • grep -win "text_to_find" ./* | Returns results with line numbers in all files in current directory + Will throw error for any subdirectory that might be present.
  • grep -win "text_to_find" ./*.txt | Doesn’t try to search in any subdirectory.
  • grep -winr "text_to_find" . | To search every file and through every subdirectory, a recursive search, might get lot of results.
  1. Getting some additional context of where this match is found, see a certain number of lines before and after a match.
  • grep -win -B 4 "text_to_find" <file_name> | 4 lines Before all of our match
  • grep -win -A 4 "text_to_find" <file_name> | 4 lines After all of our match
  • grep -win -C 2 "text_to_find" <file_name> | 2 lines Before and After all of our match
  1. If you’re only interested in file_names with the matches, NOT in the matches themselves.
  • grep -wirl "text_to_find" . | Recursive result of all files with the match
  • grep -wirc "text_to_find" . | Recursive result of all files with the match + Number of matches in each file

Pipe the output of other commands in to grep to search for something

  • history | grep "git commit"
  • history | grep "git commit" | grep "dotfile"
grep uses Posix regular expressions by default
  • grep "...-...-...." <filename>
  • grep "\d{3}-\d{3}-\d{4}" <filename> | This wouldn’t work, because this is pro compatible regular expressions which grep doesn’t use.
  • grep -P "\d{3}-\d{3}-\d{4}" <filename> | This would allow it to work on Linux, NOT on Mac
  • grep -wirlP "\d{3}-\d{3}-\d{4}" <filename> | Return recursive list of list with matching phone numbers
  • grep -V
    • Mac uses BSD grep
    • Linux uses GNU grep`
  • brew install grep --with-default-names
    • --with-default-names | It will install it as grep, else as ggrep (allowing us to use both BSD and GNU grep)