find (unix command)

Related: 2024-10-07 Unix Lecture 4, exec-find-unix-command, Programming MOC

Summary
Difference between find and grep: find is used to find files in one or multiple directories, and grep is used to find content inside files.

Find

• powerful search command, searches files in a repo

find repo_to_search [-criteria] [-actions]

• important to put -print at the end, to make sure whatever files you’re searching for actually print!
• access level - to go through files, find needs access to those files. Otherwise they won’t show up in the search
• search files by age, size, owner, file type, timestamp, permissions, and depth within subtree
• can also do things to the files themselves

Examples of Find

find all files that start with “A” or “a”, followed by letters or numbers, and end with a number between 3 and 6

find . -iname "a*[3-6]" -print
 
OR
 
find . -name "[aA]*[3-6]" -print

find a file that was modified 30 days ago, more than 30 days ago, and less than 30 days ago?

find . -mtime 30 -print
 
find . -mtime +30 -print
 
find . -mtime -30 -print

find only directories

find . -type d -print

find a file that was modified less than 12 days ago and is larger than 30K

find . -type f -mtime -12 -size +30 k -print

Find Search Criteria

find -amin n

• find files that were accessed n minutes ago
  find -anewer folder-name
• searches most recently access files from folder-name
  find -atime *n
• searches files accessed n days (24 hour period)
• just n = exactly n, +n = more than n, and -n = less than n
  -cmin n
  -cnewer folder-name
  -ctime n
  -mmin n
• find files that were modified n minutes
  -mtime n
• find files that were modified n days (24 hour period)
  -name file-name
  -iname file-name
  -size n
  -user user-name
  -group group-name
  -type d/f
• d = directory
• f = file
  -empty
• search all empty files and directories

Find vs Locate

Bottom line, both are very useful. locate(1) is better when you’re just trying to find a particular file by name, which you know exists, but you just don’t remember where it is exactly. find(1) is better when you have a focused area to examine, or when you need any of its many advantages. ([source](files - locate vs find: usage, pros and cons of each other - Unix & Linux Stack Exchange)

Find vs Grep

The Major difference is FIND is for searching files and directories using filters while GREP is for searching a pattern inside a file or searching process(es)_

FIND is an command for searching file(s) and folder(s) using filters such as size , access time , modification time.

The find command lists all of the files within a directory and its sub-directories that match a set of filters.

This command is most commonly used to find all of the files that have a certain name.

To find all of the files named theFile.txt in your current directory and all of its sub-directories, enter:

find . -name theFile.txt -print

To look in your current directory and its sub-directories for all of the files that end in the extension .txt , enter:

find . -name "*.txt" -print

GREP :(Globally search a Regular Expression and Print)
Searches files for a specified string or expression.

Grep searches for lines containing a specified pattern and, by default, writes them to the standard output.

grep myText theFile.txt

Result : Grep will print out each line contain the word myText. source

flashcards

• using find, how do you return only files in your search results? // use -type f to specify files
• using find, how do you return only directories in your search results? // use -type d to specify directories
• what does find . -type d mean? // find all directories in the current directory
• what does find . -type f mean? // find all files in the current directory
• what does find . "*.c" -print mean? // find all files in current directory that has a c at the end with a character before it and print the results
• what does find / -mtime -3 -print mean? // find all files in the entire tree that were modified less than 3 days ago
• what’s the difference between find / and find ~ ? // find / looks through all files in the tree, while find ~ looks through all the content in your user account

references/links

• files - locate vs find: usage, pros and cons of each other - Unix & Linux Stack Exchange
• unix - What is the difference between find with grep? - Stack Overflow

note created on 20241130 @ 2100