reverse.md

reverse

Reverse order of rows in a CSV. Unlike the sort --reverse command, it preserves the order of rows with the same key. If an index is present, it works with constant memory. Otherwise, it will load all the data into memory.

Table of Contents | Source: src/cmd/reverse.rs | 📇🤯

Description | Usage | Common Options

Description ↩

Reverses rows of CSV data.

Useful for cases when there is no column that can be used for sorting in reverse order, or when keys are not unique and order of rows with the same key needs to be preserved.

Note that if the CSV is not indexed, this operation will require reading all of the CSV data into memory

Usage ↩

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

Common Options ↩

Option	Type	Description	Default
‑h, ‑‑help	flag	Display this message
‑o, ‑‑output	string	Write output to instead of stdout.
‑n, ‑‑no‑headers	flag	When set, the first row will not be interpreted as headers. Namely, it will be reversed with the rest of the rows. Otherwise, the first row will always appear as the header row in the output.
‑d, ‑‑delimiter	string	The field delimiter for reading CSV data. Must be a single character. (default: ,)
‑‑memcheck	flag	Check if there is enough memory to load the entire CSV into memory using CONSERVATIVE heuristics.

---

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