msgcat
concatenates and merges gettext PO files
TLDR
Concatenate PO files
$ msgcat [file1.po] [file2.po] -o [combined.po]
Merge with unique messages$ msgcat --use-first [file1.po] [file2.po] -o [output.po]
Sort messages$ msgcat --sort-output [input.po] -o [sorted.po]
Remove duplicates$ msgcat --unique [input.po] -o [output.po]
SYNOPSIS
msgcat [options] inputfile...
DESCRIPTION
msgcat concatenates and merges gettext PO files. Combines multiple translation files, handles duplicates, and normalizes output. Part of GNU gettext for managing internationalization catalogs.
PARAMETERS
-o file
Output file.--use-first
Use first translation for duplicates.--sort-output
Sort messages alphabetically.--unique
Remove duplicate messages.-t encoding
Output encoding.

