append

Concatenates tab-separated values (TSV) files, similar to Unix cat, but with header awareness and optional source tracking.

Input:

• Reads from files or standard input.
• Files ending in .gz are transparently decompressed.

Header behavior:

• Supports --header / -H and --header-hash1 modes.
• When using header mode with multiple files, only the header from the first file is written; headers from subsequent files are skipped.

Source tracking:

• --track-source / -t: Adds a column containing the source name for each data row. For regular files, the source name is the file name without extension. For standard input, the source name is stdin.
• --source-header / -s STR: Sets the header for the source column. Implies --header and --track-source. Default header name is file.
• --file / -f LABEL=FILE: Reads FILE and uses LABEL as the source value. Implies --track-source.

Output:

• By default, output is written to standard output.
• Use --outfile to write to a file instead.

Examples:

1. Concatenate multiple files with header tva append -H file1.tsv file2.tsv file3.tsv

2. Track source file for each row tva append -H -t file1.tsv file2.tsv

3. Use custom source labels tva append -H -f A=file1.tsv -f B=file2.tsv