msgcomm Command in Linux
msgcomm is a Linux command-line tool used in software development for comparing message catalogs. It is part of the GNU gettext utilities, which are essential for internationalization and localization of software. This tool helps developers identify common and unique translations across multiple .po files (Portable Object files). By comparing these files, developers can ensure consistency and completeness in their translations.
Table of Contents
Here is a comprehensive guide to the options available with the msgcomm command −
Syntax of msgcomm Command
To run the msgcomm command in Linux, use the following basic syntax −
msgcomm [options] file1.po file2.po ... filen.po
Where −
- [options] are optional parameters that modify the command's behavior.
- po, file2.po, ..., filen.po are the Portable Object files you want to compare.
msgcomm Command Options
Here are some various options you can apply with the Linux msgcomm command −
Input File Location
| Option | Description |
|---|---|
| inputfile ... | Lists the files that are used as input. |
| -f file, --files-from=file | Reads the names of input files from the specified file instead of the command line. |
| -D directory, --directory=directory | Adds the given directory to the search path for input files. |
Output File Location
| Option | Description |
|---|---|
| -o file, --output-file=file | Writes the output to the specified file. |
Message Selection
| Option | Description |
|---|---|
| -< number, --less-than=number | Outputs messages with fewer than the specified number of definitions. Defaults to infinite if not set. |
| -> number, --more-than=number | Outputs messages with more than the specified number of definitions. Defaults to 1 if not set. |
| -u, --unique | Equivalent to --less-than=2. Outputs only unique messages. |
Input File Syntax
| Option | Description |
|---|---|
| -P, --properties-input | Treats the input files as Java ResourceBundles in .properties format, not as PO files. |
| --stringtable-input | Treats the input files as NeXTstep/GNUstep localized resource files in .strings format, not as PO files. |
Output Details
| Option | Description |
|---|---|
| --color, --color=when | Determines when to use colors and text attributes. |
| --style=style_file | Specifies the CSS style rule file to use for --color. |
| --force-po | Always creates an output file even if there are no messages. |
| -i, --indent | Writes the .po file in an indented format. |
| --no-location | Omits the #: filename:line lines |
| -n, --add-location=type | Generates the #: filename:line lines (default behavior). |
| --strict | Produces a PO file that strictly conforms to the Uniforum standard. |
| -p, --properties-output | Outputs a Java ResourceBundle in .properties format. |
| --stringtable-output | Outputs a NeXTstep/GNUstep localized resource file in .strings format. |
| -w number, --width=number | Sets the width of the output page. |
| --no-wrap | Prevents long message lines from being split. |
| -s, --sort-output | Produces sorted output. |
| -F, --sort-by-file | Sorts the output by file location. |
| --omit-header | Does not include the header with the msgid "" entry. |
Informative Output
| Option | Description |
|---|---|
| -h, --help | Display this help and exit. |
| -V, --version | Output version information and exit. |
Examples of msgcomm Command in Linux
Below are a few examples demonstrating how to use the command msgcomm in different scenarios on Linux environment −
- Basic Comparison
- Reading Input Files from List
- Specifying Output File
- Less than a Number of Definitions
- More than a Number of Definitions
- Unique Messages
Basic Comparison
To perform a basic comparison between multiple .po files −
msgcomm file1.po file2.po file3.po
This command compares file1.po, file2.po, and file3.po, highlighting the common messages found across these files. This is useful for identifying translations that are consistent across different files.
Reading Input Files from List
If you have a list of input files, you can read them using the -f option −
msgcomm -f file_list.txt
This approach allows you to specify a file, file_list.txt, containing the names of the .po files to compare. This is helpful when dealing with a large number of files, as it simplifies the command line input.
Specifying Output File
To direct the comparison results to a specific output file, use the -o option −
msgcomm -o result.po file1.po file2.po file3.po
This command saves the common messages from file1.po, file2.po, and file3.po into result.po. This allows you to easily review and manage the results in a single file.
Less Than a Number of Definitions
To filter messages that appear in less than a specified number of files, use the --less-than option −
msgcomm --less-than=2 file1.po file2.po file3.po
This will display messages that are present in fewer than two of the provided .po files. This is useful for identifying translations that are less commonly used across your catalog.
More Than a Number of Definitions
For displaying messages that occur in more than a specified number of files, use the --more-than option −
msgcomm --more-than=1 file1.po file2.po file3.po
This command shows messages appearing in more than one of the specified .po files. This is helpful for focusing on translations that are widely used and ensuring their consistency.
Unique Messages
To identify messages that are unique to each file, use the -u option −
msgcomm -u file1.po file2.po file3.po
This command highlights messages that are unique, showing entries that appear in only one of the specified .po files. This can help you identify translations that may need to be reviewed or added to other files.
Conclusion
msgcomm is an essential tool for developers working on the internationalization and localization of software. By comparing message catalogs, it ensures that translations are consistent and accurate.
Whether performing basic comparisons, specifying input directories, or including fuzzy translations, msgcomm provides the necessary functionality to maintain high-quality translations. By following this guide, you can effectively use msgcomm to manage and verify your software translations.