docs/docs/4.4/cmds/string-join0.html
string join [-q | --quiet] [-n | --no-empty] [--] SEP [STRING ...]string join0 [-q | --quiet] [-n | --no-empty] [--] [STRING ...]
Joins its STRING arguments into a single string separated by SEP (for string join) or by the zero byte (NUL) (for string join0). Exit status: 0 if at least one join was performed, or 1 otherwise.
-n , --no-empty
Exclude empty strings from consideration (e.g. string join -n + a b "" c would expand to a+b+c not a+b++c).
-q , --quiet
Do not print the strings, only set the exit status as described above.
WARNING : Insert a -- before positional arguments to prevent them from being interpreted as flags. Otherwise, any strings starting with - will be treated as flag arguments, meaning they will most likely result in the command failing. This is also true if you specify a variable which expands to such a string instead of a literal string. If you don’t need to append flag arguments at the end of the command, just always use -- to avoid unwelcome surprises.
string join0 adds a trailing NUL. This is most useful in conjunction with tools that accept NUL-delimited input, such as sort -z.
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.
\>\_ 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 cabc\>\_ set -l markdown\_list '- first' '- second' '- third'# Strings with leading hyphens (also in variable expansions) are interpreted as flag arguments by default.\>\_ string join \n $markdown\_liststring join: - first: unknown option# Use '--' to prevent this.\>\_ string join -- \n $markdown\_list- first- second- third