nushell/crates/nu-std/std/dirs.nu
2023-10-02 21:13:31 +03:00

145 lines
4.1 KiB
Plaintext

# Maintain a list of working directories and navigate them
# The directory stack.
#
# Exception: the entry for the current directory contains an
# irrelevant value. Instead, the source of truth for the working
# directory is $env.PWD. It has to be this way because cd doesn't
# know about this module.
#
# Example: the following state represents a user-facing directory
# stack of [/a, /var/tmp, /c], and we are currently in /var/tmp .
#
# PWD = /var/tmp
# DIRS_POSITION = 1
# DIRS_LIST = [/a, /b, /c]
#
# This situation could arise if we started with [/a, /b, /c], then
# we changed directories from /b to /var/tmp.
export-env {
$env.DIRS_POSITION = 0
$env.DIRS_LIST = [($env.PWD | path expand)]
}
# Add one or more directories to the list.
# PWD becomes first of the newly added directories.
export def --env add [
...paths: string # directory or directories to add to working list
] {
mut abspaths = []
for p in $paths {
let exp = ($p | path expand)
if ($exp | path type) != 'dir' {
let span = (metadata $p).span
error make {msg: "not a directory", label: {text: "not a directory", start: $span.start, end: $span.end } }
}
$abspaths = ($abspaths | append $exp)
}
$env.DIRS_LIST = ($env.DIRS_LIST | insert ($env.DIRS_POSITION + 1) $abspaths | flatten)
_fetch 1
}
export alias enter = add
# Advance to the next directory in the list or wrap to beginning.
export def --env next [
N:int = 1 # number of positions to move.
] {
_fetch $N
}
export alias n = next
# Back up to the previous directory or wrap to the end.
export def --env prev [
N:int = 1 # number of positions to move.
] {
_fetch (-1 * $N)
}
export alias p = prev
# Drop the current directory from the list, if it's not the only one.
# PWD becomes the next working directory
export def --env drop [] {
if ($env.DIRS_LIST | length) > 1 {
$env.DIRS_LIST = ($env.DIRS_LIST | reject $env.DIRS_POSITION)
if ($env.DIRS_POSITION >= ($env.DIRS_LIST | length)) {$env.DIRS_POSITION = 0}
}
# step to previous slot
_fetch -1 --forget_current --always_cd
}
export alias dexit = drop
# Display current working directories.
export def --env show [] {
mut out = []
for $p in ($env.DIRS_LIST | enumerate) {
let is_act_slot = $p.index == $env.DIRS_POSITION
$out = ($out | append [
[active, path];
[($is_act_slot),
(if $is_act_slot {$env.PWD} else {$p.item}) # show current PWD in lieu of active slot
]
])
}
$out
}
export alias shells = show
export def --env goto [shell?: int] {
if $shell == null {
return (show)
}
if $shell < 0 or $shell >= ($env.DIRS_LIST | length) {
let span = (metadata $shell | get span)
error make {
msg: $"(ansi red_bold)invalid_shell_index(ansi reset)"
label: {
text: $"`shell` should be between 0 and (($env.DIRS_LIST | length) - 1)"
start: $span.start
end: $span.end
}
}
}
$env.DIRS_POSITION = $shell
cd ($env.DIRS_LIST | get $env.DIRS_POSITION)
}
export alias g = goto
# fetch item helper
def --env _fetch [
offset: int, # signed change to position
--forget_current # true to skip saving PWD
--always_cd # true to always cd
] {
if not ($forget_current) {
# first record current working dir in current slot of ring, to track what CD may have done.
$env.DIRS_LIST = ($env.DIRS_LIST | upsert $env.DIRS_POSITION $env.PWD)
}
# figure out which entry to move to
# nushell 'mod' operator is really 'remainder', can return negative values.
# see: https://stackoverflow.com/questions/13683563/whats-the-difference-between-mod-and-remainder
let len = ($env.DIRS_LIST | length)
mut pos = ($env.DIRS_POSITION + $offset) mod $len
if ($pos < 0) { $pos += $len}
# if using a different position in ring, CD there.
if ($always_cd or $pos != $env.DIRS_POSITION) {
$env.DIRS_POSITION = $pos
cd ($env.DIRS_LIST | get $pos )
}
}