fixedwidth

July 9, 2026 · View on GitHub

Convert fixed-width text (fields at fixed byte-column positions, no delimiters) to CSV.

Table of Contents | Source: src/cmd/fixedwidth.rs

Description | Examples | Usage | Fixedwidth Options | Common Options

Description ↩

Converts fixed-width text (fields at fixed byte-column positions, no delimiters) to CSV.

By default, this expects the input's first line to be a comment enumerating the 1-based starting byte position of each column, comma-separated and prefixed with "#" - the same format qsv table --align leftfwf produces (e.g. "#1,10,15"). Every subsequent line is a data record; each field runs from its starting position up to (but not including) the next column's starting position, or to the end of the line for the last column. Trailing whitespace in each field is trimmed.

If the input doesn't have such a header comment - e.g. it comes from an external system - specify the column positions explicitly with --positions, or column widths with --widths.

Examples ↩

Convert output of qsv table --align leftfwf back to CSV:

qsv table --align leftfwf data.csv | qsv fixedwidth > roundtrip.csv

Convert a file with explicit 1-based column start positions:

qsv fixedwidth --positions 1,10,15 mainframe_extract.txt

Convert a file with explicit column widths instead of positions:

qsv fixedwidth --widths 9,5,20 mainframe_extract.txt

Usage ↩

qsv fixedwidth [options] [<input>]
qsv fixedwidth --help

Fixedwidth Options ↩

Option	Type	Description	Default
`‑‑positions`	string	Comma-separated, 1-based starting byte position of each column (e.g. "1,10,15"). Overrides any "#..." header comment in the input.
`‑‑widths`	string	Comma-separated width, in bytes, of each column (e.g. "9,5,20"). An alternative to --positions; the two are mutually exclusive.

Common Options ↩

Option	Type	Description	Default
`‑h,` `‑‑help`	flag	Display this message
`‑o,` `‑‑output`	string	Write output to instead of stdout.

Source: src/cmd/fixedwidth.rs | Table of Contents | README