check

Validates the structure of TSV input by ensuring that all lines have the same number of fields.

Behavior:

• Without header mode: The number of fields on the first line is used as the expected count.
• With header mode: The number of fields in the header’s column names line is used as the expected count.
• Each subsequent line must have the same number of fields.
• On mismatch, details about the failing line and expected field count are printed to stderr and the command exits with a non-zero status.

Input:

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

Header behavior:

• Supports all four header modes. See tva --help-headers for details.
• When header mode is enabled, the header lines are skipped from structure checking.
• The field count from the header’s column names line is used as the expected count.

Output:

• On success, prints: <N> lines total, <M> data lines, <P> fields