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fish-config/functions/jobrunner.fish
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Fish

# Copyright (C) 2026 Rootiest
# SPDX-License-Identifier: AGPL-3.0-or-later
# CATEGORY
# 08-terminal-management
#
# DEPENDENCIES
# tmux, screen, __jobrunner_sessions
#
# SYNOPSIS
# jobrunner [-t <tool>] [<subcommand>] [<name>] [<command>...]
# jr [-t <tool>] [<subcommand>] [<name>] [<command>...]
#
# DESCRIPTION
# Runs, lists, inspects, re-attaches to, and terminates named background
# jobs using tmux or GNU screen as the process engine. Unlike bkg and
# detach, which discard output, a jobrunner job keeps a live terminal you
# can return to later — it survives closing the shell, and `attach`
# restores it in any subsequent session.
#
# Every subcommand has a matching flag form, and the common cases are
# inferred: no arguments lists jobs, a lone name attaches to it, and a
# name followed by a command runs it.
#
# ARGUMENTS
# -t, --tool <name> Force specific backend (tmux or screen)
# run, -r, --run <name> <cmd>... Start a named job in the background
# list, -l, --list List all managed background jobs
# attach, -a, --attach <name> Re-attach interactively to a job
# kill, -k, --kill <name> Terminate a running background job
# logs, -o, --output <name> Print a job's current output, no attach
# help, -h, --help Show usage help
#
# EXIT STATUS
# 0 Command succeeded, or no jobs are running
# 1 Invalid arguments, or the named job does not exist
# 127 neither tmux nor screen is installed
#
# EXAMPLE
# jobrunner run build make -j8
# jobrunner -t screen run backup rsync -a ./data remote:/backup/
# jobrunner list
# jobrunner logs build
# jobrunner build
# jobrunner kill build
#
# NOTES
# Detach from an attached job with Ctrl-A then D; the job keeps running.
# Commands are executed directly rather than through a shell, so pipes and
# redirections must be wrapped explicitly, e.g.
# `jobrunner run sync fish -c 'a | b'`.
function jobrunner --description 'Manage detached background jobs with tmux or GNU screen'
set -l c_head (set_color --bold cyan)
set -l c_cmd (set_color --bold white)
set -l c_arg (set_color cyan)
set -l c_flag (set_color yellow)
set -l c_ok (set_color green)
set -l c_err (set_color red)
set -l c_dim (set_color brblack)
set -l c_rst (set_color normal)
set -l subcmds run list attach kill logs help \
-r --run -l --list -a --attach -k --kill -o --output -h --help
# ╭──────────────────────────────────────────────────────────╮
# │ Tool Extraction │
# ╰──────────────────────────────────────────────────────────╯
set -l tool ""
while test (count $argv) -gt 0
switch $argv[1]
case -t
set tool $argv[2]
set -e argv[1..2]
case --tool
set tool $argv[2]
set -e argv[1..2]
case '--tool=*'
set tool (string replace -- "--tool=" "" $argv[1])
set -e argv[1]
case '-t*'
set tool (string replace -r "^-t" "" $argv[1])
set -e argv[1]
case '*'
break
end
end
# ╭──────────────────────────────────────────────────────────╮
# │ Help │
# ╰──────────────────────────────────────────────────────────╯
# Answered before the dependency check so usage is readable anywhere.
if set -q argv[1]; and contains -- $argv[1] help -h --help
echo "$c_head""Usage:$c_rst $c_cmd""jobrunner$c_rst $c_arg""[<subcommand>] [<name>] [<command>...]$c_rst"
echo
echo " Run and manage named background jobs backed by tmux or GNU screen."
echo
echo "$c_head""Subcommands:$c_rst"
echo " $c_cmd""run$c_rst $c_arg""<name> <cmd>...$c_rst Start a named job in the background"
echo " $c_cmd""list$c_rst List all managed background jobs"
echo " $c_cmd""attach$c_rst $c_arg""<name>$c_rst Re-attach interactively to a job"
echo " $c_cmd""kill$c_rst $c_arg""<name>$c_rst Terminate a running background job"
echo " $c_cmd""logs$c_rst $c_arg""<name>$c_rst Print a job's output without attaching"
echo
echo "$c_head""Flags:$c_rst"
echo " $c_flag-t$c_rst, $c_flag--tool$c_rst $c_arg<name>$c_rst Force specific backend (tmux or screen)"
echo " $c_flag-r$c_rst, $c_flag--run$c_rst Same as $c_cmd""run$c_rst"
echo " $c_flag-l$c_rst, $c_flag--list$c_rst Same as $c_cmd""list$c_rst"
echo " $c_flag-a$c_rst, $c_flag--attach$c_rst Same as $c_cmd""attach$c_rst"
echo " $c_flag-k$c_rst, $c_flag--kill$c_rst Same as $c_cmd""kill$c_rst"
echo " $c_flag-o$c_rst, $c_flag--output$c_rst Same as $c_cmd""logs$c_rst"
echo " $c_flag-h$c_rst, $c_flag--help$c_rst Show this help message"
echo
echo "$c_head""Shorthands:$c_rst"
echo " $c_cmd""jobrunner$c_rst $c_dim""list$c_rst"
echo " $c_cmd""jobrunner$c_rst $c_arg""<name>$c_rst $c_dim""attach <name>$c_rst"
echo " $c_cmd""jobrunner$c_rst $c_arg""<name> <cmd>...$c_rst $c_dim""run <name> <cmd>...$c_rst"
echo
echo "$c_head""Examples:$c_rst"
echo " $c_cmd""jobrunner$c_rst $c_arg""run build$c_rst""$c_dim"" make -j8$c_rst"
echo " $c_cmd""jobrunner$c_rst $c_arg""logs build$c_rst"
echo " $c_cmd""jobrunner$c_rst $c_arg""kill build$c_rst"
echo
echo "$c_dim""Detach from an attached job with Ctrl-A then D.$c_rst"
return 0
end
# ╭──────────────────────────────────────────────────────────╮
# │ Dependency check │
# ╰──────────────────────────────────────────────────────────╯
if test -n "$tool"
if not contains -- $tool tmux screen
echo "$c_err""jobrunner:$c_rst invalid tool '$c_arg$tool$c_rst', must be 'tmux' or 'screen'." >&2
return 1
end
if not command -q $tool
echo "$c_err""jobrunner:$c_rst '$tool' is required but was not found in PATH." >&2
return 127
end
else
if command -q tmux
set tool tmux
else if command -q screen
set tool screen
else
echo "$c_err""jobrunner:$c_rst neither 'tmux' nor 'screen' was found in PATH." >&2
return 127
end
end
# ╭──────────────────────────────────────────────────────────╮
# │ Argument pre-processing │
# ╰──────────────────────────────────────────────────────────╯
set -q argv[1]; or set argv list
set -l cmd $argv[1]
if not contains -- $cmd $subcmds
if test (count $argv) -eq 1
# A lone name attaches, but only if that job actually exists.
if contains -- $cmd (__jobrunner_sessions $tool | string replace -r '\t.*$' '')
set argv attach $argv
set cmd attach
else
echo "$c_err""jobrunner:$c_rst unknown subcommand or job '$c_arg$cmd$c_rst'." >&2
echo "Run $c_cmd""jobrunner --help$c_rst for usage." >&2
return 1
end
else
# A name plus a command line is an implicit run.
set argv run $argv
set cmd run
end
end
# ╭──────────────────────────────────────────────────────────╮
# │ Dispatch │
# ╰──────────────────────────────────────────────────────────╯
switch $cmd
case run -r --run
if test (count $argv) -lt 3
echo "$c_head""Usage:$c_rst $c_cmd""jobrunner run$c_rst $c_arg""<name> <command>...$c_rst" >&2
return 1
end
set -l name $argv[2]
set -l task $argv[3..-1]
# screen stores each session as a socket file named after it.
if string match -q '*/*' -- $name
echo "$c_err""jobrunner:$c_rst job name may not contain '/'." >&2
return 1
end
if contains -- $name (__jobrunner_sessions $tool | string replace -r '\t.*$' '')
echo "$c_err""jobrunner:$c_rst job '$c_arg$name$c_rst' is already running." >&2
return 1
end
if test "$tool" = tmux
command tmux new-session -d -s $name $task
else
command screen -d -m -S $name $task
end
or begin
echo "$c_err""jobrunner:$c_rst failed to start job '$c_arg$name$c_rst'." >&2
return 1
end
set -l pid
for row in (__jobrunner_sessions $tool)
set -l f (string split \t -- $row)
test "$f[1]" = "$name"; and set pid $f[2]; and break
end
if set -q pid[1]
echo "$c_ok""✔$c_rst Started job $c_arg$name$c_rst $c_dim(PID $pid)$c_rst"
else
# The job may have finished (or failed) before we looked.
echo "$c_ok""✔$c_rst Started job $c_arg$name$c_rst $c_dim(already exited)$c_rst"
end
case list -l --list
set -l rows (__jobrunner_sessions $tool)
if test (count $rows) -eq 0
echo "No background jobs running."
return 0
end
printf '%s%-20s %-8s %-10s %s%s\n' "$c_head" JOB PID STATE STARTED "$c_rst"
for row in $rows
set -l f (string split \t -- $row)
printf '%s%-20s%s %-8s %-10s %s%s%s\n' \
"$c_arg" $f[1] "$c_rst" $f[2] $f[3] "$c_dim" $f[4] "$c_rst"
end
case attach -a --attach
if test (count $argv) -ne 2
echo "$c_head""Usage:$c_rst $c_cmd""jobrunner attach$c_rst $c_arg""<name>$c_rst" >&2
return 1
end
set -l name $argv[2]
if not contains -- $name (__jobrunner_sessions $tool | string replace -r '\t.*$' '')
echo "$c_err""jobrunner:$c_rst no such job '$c_arg$name$c_rst'." >&2
return 1
end
if test "$tool" = tmux
command tmux attach-session -t $name
else
# -x attaches to an already-attached session instead of failing.
command screen -x $name
end
case kill -k --kill
if test (count $argv) -ne 2
echo "$c_head""Usage:$c_rst $c_cmd""jobrunner kill$c_rst $c_arg""<name>$c_rst" >&2
return 1
end
set -l name $argv[2]
if not contains -- $name (__jobrunner_sessions $tool | string replace -r '\t.*$' '')
echo "$c_err""jobrunner:$c_rst no such job '$c_arg$name$c_rst'." >&2
return 1
end
if test "$tool" = tmux
command tmux kill-session -t $name
else
command screen -X -S $name quit
end
or begin
echo "$c_err""jobrunner:$c_rst failed to terminate job '$c_arg$name$c_rst'." >&2
return 1
end
echo "$c_ok""✔$c_rst Terminated job $c_arg$name$c_rst"
case logs -o --output
if test (count $argv) -ne 2
echo "$c_head""Usage:$c_rst $c_cmd""jobrunner logs$c_rst $c_arg""<name>$c_rst" >&2
return 1
end
set -l name $argv[2]
if not contains -- $name (__jobrunner_sessions $tool | string replace -r '\t.*$' '')
echo "$c_err""jobrunner:$c_rst no such job '$c_arg$name$c_rst'." >&2
return 1
end
set -l out
if test "$tool" = tmux
# capture-pane -S - -p outputs the scrollback and current pane directly to stdout.
set out (command tmux capture-pane -t $name -S - -p)
or begin
echo "$c_err""jobrunner:$c_rst could not read output of '$c_arg$name$c_rst'." >&2
return 1
end
else
# hardcopy -h dumps scrollback plus the visible screen to a file.
# ponytail: snapshot only; add `screen -L` logging if full
# since-start history is ever needed.
set -l dump (command mktemp)
command screen -X -S $name hardcopy -h $dump
or begin
command rm -f $dump
echo "$c_err""jobrunner:$c_rst could not read output of '$c_arg$name$c_rst'." >&2
return 1
end
set out (command cat $dump)
command rm -f $dump
end
# hardcopy (and sometimes tmux) pad the dump with empty lines.
while set -q out[1]; and test -z "$out[-1]"
set -e out[-1]
end
if set -q out[1]
printf '%s\n' $out
else
echo "$c_dim(no output yet)$c_rst"
end
case '*'
echo "$c_err""jobrunner:$c_rst invalid subcommand '$c_arg$cmd$c_rst'." >&2
echo "Run $c_cmd""jobrunner --help$c_rst for usage." >&2
return 1
end
end