Example Use Cases of the `touch` Command (with examples)

Use Case 1: Create specific files

Code:

touch path/to/file1 path/to/file2 ...

Motivation:

Sometimes we may need to create multiple files at once. By using the touch command with the desired file paths, we can quickly create all the files in one go.

Explanation:

The touch command is used to create files with the specified paths. By providing the desired file paths as arguments, the command will create the files if they do not already exist. If the files already exist, the command will only update the access/modification times of the files without modifying their content.

Example Output:

If we run the command touch file1.txt file2.txt, it will create two files named file1.txt and file2.txt in the current directory. If these files did not exist previously, they will be created empty. If they already exist, their access/modification times will be updated.

Use Case 2: Set file access or modification times to the current one and don’t create file if it doesn’t exist

Code:

touch -c -a|m path/to/file1 path/to/file2 ...

Motivation:

There are situations where we may want to update the access or modification times of files without creating them if they do not already exist. This can be useful for managing the timestamp information of files within a directory.

Explanation:

The -c flag tells the touch command not to create any files, while the -a (access time) and -m (modification time) flags specify which timestamps to update. By using this combination of flags, we can update the access or modification times of existing files without creating new ones.

Example Output:

Assuming we have an existing file named example.txt, running touch -c -a example.txt will update the access time of the file to the current time. Similarly, running touch -c -m example.txt will update the modification time to the current time. The command will not create a new file if it does not already exist.

Use Case 3: Set file time to a specific value and don’t create file if it doesn’t exist

Code:

touch -c -t YYYYMMDDHHMM.SS path/to/file1 path/to/file2 ...

Motivation:

In certain scenarios, we may need to set the timestamp of a file to a specific value, either for debugging purposes or to align with other files in a specific order.

Explanation:

The -c flag, as mentioned previously, prevents the touch command from creating any new files. The -t flag allows us to specify a specific timestamp in the format YYYYMMDDHHMM.SS. By using this flag in combination with the desired timestamp, we can set the file time to the specified value without creating new files.

Example Output:

Suppose we want to set the timestamp of a file named data.txt to January 1, 2022, at 10:30 AM. Running touch -c -t 202201011030.00 data.txt will update the file’s timestamp to the specified value. If the file does not exist, it will not be created.

Use Case 4: Set file time of a specific file to the time of another file and don’t create file if it doesn’t exist

Code:

touch -c -r path/to/source_file path/to/destination_file

Motivation:

In some situations, we may want to synchronize the timestamps of two files, either to maintain consistency or to propagate the timestamp of one file onto another.

Explanation:

The -c flag prevents the touch command from creating a new file if the destination file does not already exist. The -r flag allows us to specify a source file from which to copy the timestamp. By providing the paths of the source file and the destination file, the touch command will update the timestamp of the destination file to match the timestamp of the source file.

Example Output:

Suppose we have two files, source.txt and destination.txt. Running touch -c -r source.txt destination.txt will update the timestamp of destination.txt to match that of source.txt. If destination.txt does not exist, it will not be created. This allows us to synchronize the timestamps of the two files without modifying their content.