string-join - join strings with delimiter — fish-shell 3.7.1 documentation

# string-join - join strings with delimiter

## Synopsis

    string join [-q | --quiet] SEP [STRING ...]
    string join0 [-q | --quiet] [STRING ...]

## Description

`string join` joins its STRING arguments into a single string separated by SEP, which can be an empty string. Exit status: 0 if at least one join was performed, or 1 otherwise. If `-n` or `--no-empty` is specified, empty strings are excluded from consideration (e.g. `string join -n + a b "" c` would expand to `a+b+c` not `a+b++c`).

`string join0` joins its STRING arguments into a single string separated by the zero byte (NUL), and adds a trailing NUL. This is most useful in conjunction with tools that accept NUL-delimited input, such as `sort -z`. Exit status: 0 if at least one join was performed, or 1 otherwise.

Because Unix uses NUL as the string terminator, passing the output of `string join0` as an argument to a command (via a command substitution) won’t actually work. Fish will pass the correct bytes along, but the command won’t be able to tell where the argument ends. This is a limitation of Unix’ argument passing.

## Examples

    >_ seq 3 | string join ...
    1...2...3

    # Give a list of NUL-separated filenames to du (this is a GNU extension)
    >_ string join0 file1 file2 file\nwith\nmultiple\nlines | du --files0-from=-

    # Just put the strings together without a separator
    >_ string join '' a b c
    abc