How to Use All Linux Search Commands

Linux offers six different search methods, each with its own merits. We’ll show you how to use find , locate , which , whereis , whatis and apropos . Each excels at different tasks; Here’s how to choose the right tool for the job.

You are spoiled for choice when it comes to Linux search and search commands. Why so much? Well, each of them has its own characteristics, and they work better than others in certain circumstances. You could think of them as something like a Swiss army knife for searching. We will take a look at each blade in turn and figure out its strengths.

Search command

Team Behavior find difficult to determine by trial and error. Once you understand the syntax, you will begin to appreciate its flexibility and power.

The easiest way to use find — just dial find and press Enter.

  находить 

used in this way find Behave like ls but it lists all the files in the current directory and those in subdirectories.

Some implementations find require you to put . for the current directory. If this is the case on your version of Linux, use the following command:

  находить . 

To find search from root folder, you should use this command:

  находить / 

To start searching from your home folder, use this command:

  найти ~ 

Using find with file patterns

To find was something more than an automatically recursive version ls we need to provide it with something to look for. We can provide filenames or file patterns. Patterns use wildcards where * means any character string and ? means any single character.

Templates must be specified to work correctly. It’s easy to forget to do this, but if you don’t quote the pattern, find will not be able to correctly execute the command you gave it.

With this command, we will search the current folder for files that match the pattern «*. *S». This means that any filename has a file extension ending in «s». We use the option -name to let you know find we pass a filename or filename pattern.

  находить .  -имя "*. * s" 

find returns those matching files.

Note that two file extensions are two characters long and one is three characters long. This is because we used the pattern «*. *S». If we only wanted two character file extensions, we would use «*.? S.

If we knew ahead of time that we were looking for JavaScript «.js» files, we could be more specific in our file template. Also note that you can use single quotes to wrap the pattern if you like.

  находить .  -имя '* .js' 

This time find only reports on JavaScript files.

Ignoring the case with the find

If you know the name of the file you want find to find you can pass it to find instead of a template. You don’t need to enclose the filename in quotation marks unless it contains wildcards, but it’s recommended that you always do so. This means you won’t forget to use them when you need them.

  находить .  имя Yelp.js 

It didn’t return anything. But strangely, we know the file must be there. Let’s try again and say find to ignore case. We do this with the option -iname (ignore case name)

  находить.  - имя Yelp.js 

This was the problem, the filename starts with a lowercase «y» and we were looking for an uppercase «Y».

Recursive subdirectories with find

Distinctive feature find is how it recursively looks through subdirectories. Let’s find any files that start with «map».

  находить .  -имя "карта *. *" 

The relevant files are listed. Note that they are all in a subdirectory.

Search for directories with a find

Option -path allows you to search directories. Let’s look at a directory whose name we can’t remember but we know ends with ‘o’s.

  находить .  -path '* about' 

The directory is found, it’s just called «about» and is nested in another directory in the current directory.

Exists -ipath (ignore path to -ipath ) which allows you to search for paths and ignore case, similar to the option — iname described above.

Using file attributes with find

find can search for files whose attributes match the search hint. For example, you can search for empty files using the option -empty regardless of what they are called.

  находить .  -empty 

Any zero length files will be listed in the search results.

Option -executable will find any file that can be executed, such as a program or script.

  находить .  -executable 

The list of results shows a file named «fix_aptget.sh».

They also contain three directories, including «.», the current directory. The directories are included in the results because the execute bit is set in their file permissions. Without this, you won’t be able to modify («run») these directories.

-type option

Option -type allows you to search for the type of object you are looking for. We are going to provide an indicator like «f» as an option parameter -type because we want the search to only search for files.

  находить .  исполняемый тип -f 

This time the subdirectories are not listed. The script executable is the only item in the results.

We can also ask find include only directories in the results. To list all directories we can use the option -type with indicator type «d».

  находить .  тип -d 

Directories only list directories and subdirectories.

Using other commands with find

You can perform some additional actions on the found files. You can pass the files in turn to some other command.

If we need to make sure that there are no executable files in the current directory and subdirectories, we could use the following command:

  находить .  -name "fix_aptget.sh" -exec chmod -x '{}' \; 

Command means:

• Look in the current directory for a named object named «fix_aptget.sh».
• If found, run the command chmod .
• Parameters passed to chmod : -x to remove the rights to the executable file and '{}' which represents the filename of the found file.
• The last semicolon marks the end of the parameters to be passed to chmod . This needs to be «avoided» by putting a backslash in front of it.

After running this command, we can search for executable files as before, and this time there will be no files in the list.

To extend our network, we could use a file pattern instead of the filename we used in our example.

This flexibility allows you to search for files of specific types or filename patterns, and perform some action on the corresponding files.

The search has many other options, including searching for files by the date they were modified, files owned by a user or group, files that are readable, or files with a specific set of file permissions.

locate and mlocate commands

Many Linux distributions have a copy locate . This has been replaced by the command mlocate which was an improved and updated version locate .

When mlocate installed on the system, it changes the command locate so you are actually using mlocate even if you enter locate .

Current versions of Ubuntu, Fedora and Manjaro have been checked for pre-installed versions of these commands. Ubuntu and Fedora included mlocate. It had to be installed on Manjaro with this command:

  Судо Пакман -Сю Мокате 

On Ubuntu you can use locate and mlocate interchangeably. On Fedora and Manjaro, you must type locate but the command is executed for you mlocate .

If you use the option --version With locate you will see that mlocate actually mlocate .

  найти - версия 

Because the locate works on all tested Linux distributions, we will use locate in our explanation below. And that’s one letter less.

locate database

The biggest advantage locate is the speed.

When you use the command find it breaks and searches your file system. Team locate works quite differently. It searches the database to see if what you are looking for is on your computer. This makes searching much faster.

Of course, this raises the obvious question of the database. What keeps the database up to date? When mlocate is set, it (usually) puts an entry in cron.daily . This runs every day (very early in the morning) and updates the database.