Searching for files

Search for files in a hierarchy or directories using the command line.

Motivation #

In the Terminal application, programmatically searching for files or directories that match certain conditions (e.g., naming pattern) is a powerful way to apply given commands to groups of related files in a systematic way.

The find command can be used to search for files and/or directories that match certain conditions.

In particular:

• The first argument to the find command is typically the path to the directory in which to perform the search.
• The option -type takes a single character value indicating the type of file that is searched (e.g., f for file; d for directory).
• The option -name takes a Regular expression indicating a pattern that must be matched in the basename to produce a hit.

Examples are given in the following sections.

Search for files #

The example below illustrates how the find command can be used to find files – regular files, not directories – within the directory ~/ccb_demo, and whose basename end with the file extension .txt.

find ~/ccb_demo -type f -name *.txt

In particular:

• The path ~/ccb_demo is given as the first argument, indicating that the search must be performed only within that particular sub-directory of the user home directory.
• The option -type is given the value f, indicating that only regular files should be reported.
• The option -name is given the pattern *.txt, where the wildcard * matches anything, as long as the basename of the file ends with .txt.

Search for directories #

The example below illustrates how the the find command can be used to find directories within the directory ~/ccb_demo.

find ~/ccb_demo -type d

In particular:

• The path ~/ccb_demo is given as the first argument, indicating that the search must be performed only within that particular sub-directory of the user home directory.
• The option -type is given the value f, indicating that only regular files should be reported.
• The option -name is not given, meaning that no filter is applied on the basename of directories reported; in that case, all directories are reported.

Execute a command on hits #

The option -exec can be used to execute a command on each hit from the search.

For instance:

find ~/ccb_demo -type d -exec echo directory: {} \;

In particular:

• The option -exec is used to run the command echo directory: {}, where {} is a placeholder that is replaced by each hit in the search results prior to executing the command.
• The syntax \; is essential to mark the end of the command given to the -exec option.

Cheatsheet #

Common options for the find command are listed below:

For instance:

find ~/ccb_demo -mindepth 1 -maxdepth 3 -regextype posix-extended -L

Common options related to tests (i.e., filters) are listed below:

Final words #

The find command is very powerful, with many options documented in the reference manual page (accessible using the man find command).

man find