/usr/bin/mergecap

Mergecap (Wireshark) 4.4.19 (v4.4.19-0-gbb1640e38673)
Merge two or more capture files into one.
See https://www.wireshark.org for more information.

Usage: mergecap [options] -w <outfile>|- <infile> [<infile> ...]

Output:
  -a                concatenate rather than merge files.
                    default is to merge based on frame timestamps.
  -s <snaplen>      truncate packets to <snaplen> bytes of data.
  -w <outfile>|-    set the output filename to <outfile> or '-' for stdout.
                    if the output filename has the .gz extension, it will be compressed to a gzip archive
  -F <capture type> set the output file type; default is pcapng.
                    an empty "-F" option will list the file types.
  -I <IDB merge mode> set the merge mode for Interface Description Blocks; default is 'all'.
                    an empty "-I" option will list the merge modes.
  --compress <type> compress the output file using the type compression format.

Miscellaneous:
  -h, --help        display this help and exit.
  -V                verbose output.
  -v, --version     print version information and exit.