How to use the command 'run-mailcap' (with examples)

The ‘run-mailcap’ command is used to execute programs based on entries in the mailcap file, which contains information about how to handle specific mime-types or files. It allows you to perform various actions on files, such as viewing, editing, composing, and printing, by specifying the action flag. This article provides examples of different use cases for the ‘run-mailcap’ command.

Use case 1: Individual actions/programs with the ‘action’ flag

Code:

run-mailcap --action=ACTION [--option[=value]]

Motivation: This use case allows you to specify a specific action to be performed on a file using the ‘run-mailcap’ command.

Explanation:

• ‘–action=ACTION’: Specifies the action to be performed on the file. Replace ‘ACTION’ with the desired action, such as ‘view’, ’edit’, ‘compose’, or ‘print’.
• ‘–option[=value]’: Optional. Additional options to be passed to the specified action.

Example output:

run-mailcap --action=view document.pdf

This command will execute the ‘view’ action on the file ‘document.pdf’, which could open a PDF viewer to display the contents of the file.

Use case 2: Running an action on a file in simple language

Code:

run-mailcap --action=ACTION filename

Motivation: This use case provides a more simplified version of the first use case, allowing you to directly specify the action and file without additional options.

Explanation:

• ‘–action=ACTION’: Specifies the action to be performed on the file. Replace ‘ACTION’ with the desired action.
• ‘filename’: The name of the file on which the action will be performed.

Example output:

run-mailcap --action=edit document.txt

This command will execute the ’edit’ action on the file ‘document.txt’, which could open a text editor to allow modification of the file.

Use case 3: Turning on extra information

Code:

run-mailcap --action=ACTION --debug filename

Motivation: Enabling the ‘–debug’ option provides additional information about the execution of the specified action, which can be helpful for debugging purposes.

Explanation:

• ‘–action=ACTION’: Specifies the action to be performed on the file. Replace ‘ACTION’ with the desired action.
• ‘–debug’: Enables debugging mode to display extra information.

Example output:

run-mailcap --action=compose --debug email.txt

This command will execute the ‘compose’ action on the file ’email.txt’ and display detailed information about the execution process, such as debug messages or logs.

Use case 4: Ignoring “copiousoutput” directive and forwarding output to stdout

Code:

run-mailcap --action=ACTION --nopager filename

Motivation: By using the ‘–nopager’ option, you can ignore any “copiousoutput” directive in the mailcap file and forward the output directly to the standard output (stdout).

Explanation:

• ‘–action=ACTION’: Specifies the action to be performed on the file. Replace ‘ACTION’ with the desired action.
• ‘–nopager’: Ignores “copiousoutput” directive and bypasses any paging program, forwarding output to stdout.

Example output:

run-mailcap --action=print --nopager document.docx

This command will execute the ‘print’ action on the file ‘document.docx’ and directly print the file’s contents without using a pager or any intermediate program.

Use case 5: Displaying the found command without executing it

Code:

run-mailcap --action=ACTION --norun filename

Motivation: The ‘–norun’ option allows you to check what command would be executed for a given file and action without actually executing it. This can be useful for verifying the correctness of the mailcap entries.

Explanation:

• ‘–action=ACTION’: Specifies the action to be performed on the file. Replace ‘ACTION’ with the desired action.
• ‘–norun’: Displays the command that would be executed without actually running it.

Example output:

run-mailcap --action=view --norun image.png

This command will display the command that would be executed to view the file ‘image.png’ without actually opening any viewer program.

Conclusion:

The ‘run-mailcap’ command is a versatile tool for executing programs based on mime-types or file extensions. With different options and actions, it allows you to perform various operations on files, such as viewing, editing, composing, and printing. Understanding the different use cases and options of ‘run-mailcap’ can greatly enhance your productivity when working with different file types.