Formatting & Utilities Documentation

• check: Validate TSV file structure.
• nl: Add line numbers.
• keep-header: Run a shell command on the body, preserving the header.

check

Checks TSV file structure for consistent field counts.

Usage

tva check [files...]

It validates that every line in the file has the same number of fields as the first line. If a mismatch is found, it reports the error line and exits with a non-zero status.

Examples

Check a single file:

tva check docs/data/household.tsv

Output:

2 lines, 5 fields

nl

Adds line numbers to TSV rows.

Usage

tva nl [files...] [options]

Options:

• -H / --header: Treat the first line as a header. The header line is not numbered, and a “line” column is added to the header.
• -s <STR> / --header-string <STR>: Set the header name for the line number column (implies -H).
• -n <N> / --start-number <N>: Start numbering from N (default: 1).

Examples

Add line numbers (no header logic):

tva nl docs/data/household.tsv

Output:

1	family	dob_child1	dob_child2	name_child1	name_child2
2	1	1998-11-26	2000-01-29	J	K

Add line numbers with header awareness:

tva nl -H docs/data/household.tsv

Output:

line	family	dob_child1	dob_child2	name_child1	name_child2
1	1	1998-11-26	2000-01-29	J	K

keep-header

Executes a shell command on the body of a TSV file, preserving the header.

Usage

tva keep-header [files...] -- <command> [args...]

The first line of the first input file is printed immediately. The remaining lines (and all lines from subsequent files) are piped to the specified command. The output of the command is then printed.

Examples

Sort a file while keeping the header at the top:

tva keep-header data.tsv -- sort

Grep for a pattern but keep the header:

tva keep-header docs/data/world_bank_pop.tsv -- grep "AFG"

Output:

country	indicator	2000	2001
AFG	SP.URB.TOTL	4436311	4648139
AFG	SP.URB.GROW	3.91	4.66