/
Search for a File

Search for a File

Goal: How to search for a file, by name, across a hierarchy of folders.

Searching for Files:

Let us look at a folder with many subfolders and files.

[]$ cd ~/intro_to_linux [intro_to_linux]$ ls clusters data fruits.txt software.csv vegatables.txt workshop_all.txt workshop_me.txt

The ls by default only lists the first level of folders and files.

What does the -R option do?

[intro_to_linux]$ ls -R .: clusters data fruits.txt software.csv vegatables.txt workshop_all.txt workshop_me.txt ./clusters: beartooth.html loren.html teton.html wildiris.html ./data: 2021 2022 2023 dd.tx ./data/2021: Apr feb Nov README.txt Sep ./data/2021/Apr: 20210403.txt 20210427.txt 20210428.txt ./data/2021/feb: february_01_2021.tx ./data/2021/Nov: 20211114.txt 20211115.txt 20211116.txt hello.txt

Searching for Files: Recursive List Continued

./data/2021/Sep: 20210908.txt 20210921.txt ./data/2022: Dec February Hello.csv Jul Jun readme.txt ./data/2022/Dec: 20221207.txt 20221220.txt 20221230.txt 20221231.txt 2022_dec_01.txt ./data/2022/February: 20220203.txt 20220223.txt ./data/2022/Jul: 20220720.txt 20220722.txt 20220723.TX ./data/2022/Jun: 20220611.txt 20220615.txt 20220624.txt ./data/2023: Feb Jan Mar ReadMe.txt ./data/2023/Feb: 20230204.txt 20230217.txt 20230223.txt 20230224.txt ./data/2023/Jan: 20230102.txt 20230108.txt 20230115.txt 20230121.txt texttx ./data/2023/Mar: 20230305.txt 20230311.txt 20230313.txt 20230326.txt 20230327.txt HELLO.txt ./data/dd.tx:

Check the manual page:

[]$ man ls ... -R, --recursive list subdirectories recursively ...

Searching for Files: find

Command

Description

find

Usage: find [-H] [-L] [-P] [-Olevel] [-D help|tree|search|stat|rates|opt|exec] [path...] [expression] default path is the current directory; default expression is -print expression may consist of: operators, options, tests, and actions: ... EXPRESSION The part of the command line after the list of starting points is the expression. This is a kind of query specification describing how we match files and what we do ... TESTS ... -name pattern Base of file name (the path with the leading directories removed) matches shell pattern pattern. ... -iname pattern Like -name, but the match is case insensitive. ...

The find command is naturally recursive.

Examples

Find the file named: 20230121.txt

[]$ cd ~/intro_to_linux/ [intro_to_linux]$ find . -name 20230121.txt ./data/2023/Jan/20230121.txt # Check that this file is within the returned location. [intro_to_linux]$ ls data/2023/Jan/ 20230102.txt 20230108.txt 20230115.txt 20230121.txt

Find the file named: 20230120.txt

[intro_to_linux]$ find . -name 20230120.txt [intro_to_linux]$

The command completed since we got back to the prompt and no errors were displayed.

No output means that this file could not be found.

The find command is case-sensitive. Find the file with the exact filename README.txt

[intro_to_linux]$ find . -name README.txt ./data/2021/README.txt

Use the alternative -iname option to search for a file name that is case-insensitive:

[intro_to_linux]$ find . -iname README.txt ./data/2021/README.txt ./data/2022/readme.txt ./data/2023/ReadMe.txt

Examples

Use wildcards to find all files with the postfix .csv:

Lets look at two versions:

With quotes:

[intro_to_linux]$ find . -name "*.csv" ./software.csv ./data/2022/Hello.csv

Without quotes:

[intro_to_linux]$ find . -iname *.csv ./software.csv

Using or not using quotes across commands is an advanced and confusing subject.

If you do not use quotes, then if you have a file in the current directory ending with .csv, the wildcard is essentially expanded by the shell.

So, if you have a file named say "software.csv" (which we do), the command that gets executed is find . -name software.csv.

This single file is found, and the command stops.

Surrounding the search term with quotes prevents this from happening.

Find any files/folders that contain the string dec. Case-sensitive versus case-insensitive.

[intro_to_linux]$ find . -name "*dec*" ./data/2022/Dec/2022_dec_01.txt [intro_to_linux]$ find . -iname "*dec*" ./data/2022/Dec ./data/2022/Dec/2022_dec_01.txt

Find only folders using the type option and d for only directory.

Question: Are we searching with respect to case-sensitive or insensitive?

[intro_to_linux]$ find . -type d -iname "*dec*" ./data/2022/Dec

Find only files using the f (for file) value for the type option.

[intro_to_linux]$ find . -type f -iname "*dec*" ./data/2022/Dec/2022_dec_01.txt

Exercises: Find Files

Questions:

  1. What do we notice about some of the find command options?

  2. Find any files that contain the string “hello”, regardless of case, within their filename.

  3. Find any folders or files that contain the string “feb” regardless of case.

    1. Can you list only the folders?

  4. Find any files that have the postfix “tx” – must be lowercase.

Answers (1, 2)

1. What do we notice about some of the find command options?

  • That some of the single dash options (-name) are similar to long-names and not single letters.

2. Find any files that contain the string “hello”, regardless of case, within their filename.

[intro_to_linux]$ find . -name "hello" [intro_to_linux]$ find . -name "hello.*" ./data/2021/Nov/hello.txt [intro_to_linux]$ find . -iname "hello.*" ./data/2021/Nov/hello.txt ./data/2022/Hello.csv ./data/2023/Mar/HELLO.txt

Answers (3)

3. Find any folders or files that contain the string “feb” regardless of case.

  • Can you list only the folders?

[intro_to_linux]$ find . -name feb ./data/2021/feb [intro_to_linux]$ find . -iname feb ./data/2021/feb ./data/2023/Feb [intro_to_linux]$ find . -iname "*feb*" ./data/2021/feb ./data/2021/feb/february_01_2021.tx ./data/2022/February ./data/2023/Feb [intro_to_linux]$ find . -type d -iname "*feb*" ./data/2021/feb ./data/2022/February ./data/2023/Feb

Answers (4)

4. Find any files that have the postfix “tx” – must be lowercase.

[intro_to_linux]$ find . -name "tx" [intro_to_linux]$ find . -name "*tx*" ./data/2021/README.txt ./data/2021/Nov/20211115.txt ./data/2021/Nov/hello.txt ./data/2021/Nov/20211114.txt … [intro_to_linux]$ find . -name "*tx" ./data/dd.tx ./data/2021/feb/february_01_2021.tx ./data/2023/Jan/texttx [intro_to_linux]$ find . -name "*.tx" ./data/dd.tx ./data/2021/feb/february_01_2021.tx

Answers (4)

Notice: dd.tx is actually a folder, defined by the ’d’ in the long format list.

[intro_to_linux]$ ls -l data total 4 drwxrwxr-x 6 <username> <username> 2021 drwxrwxr-x 6 <username> <username> 2022 drwxrwxr-x 5 <username> <username> 2023 drwxrwxr-x 2 <username> <username> dd.tx [intro_to_linux]$ find . -type f -name "*.tx" ./data/2021/feb/february_01_2021.tx

If we (forget and) ignore the case (using iname), we would see:

[intro_to_linux]$ find . -type f -iname "*.tx" ./data/2021/feb/february_01_2021.tx ./data/2022/20220723.TX

Notice this has listed a file with a capital a postfix .TX - this is not what we wanted.

Previous

View and Search Text & Directories

Workshop Home

Intro to Linux CLI: View, Find & Search

Next

Output Redirection and Pipes