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Diffstat (limited to 'examples/acmefs/pardesctl')
| -rwxr-xr-x | examples/acmefs/pardesctl | 158 |
1 files changed, 0 insertions, 158 deletions
diff --git a/examples/acmefs/pardesctl b/examples/acmefs/pardesctl deleted file mode 100755 index 0a7bc1a4..00000000 --- a/examples/acmefs/pardesctl +++ /dev/null @@ -1,158 +0,0 @@ -#!/usr/bin/env bash -# A tiny command line over the pardes acme filesystem. bash and coreutils only: -# every subcommand below is one or two ordinary file operations, which is the -# point of serving the editor as a filesystem in the first place. -# -# WHAT IT DEMONSTRATES -# -# panes read `index` -- five %11d numbers (id, tag length, body length, -# isdir, dirty) then the tag text, one line per pane -# body read `<id>/body` tag read `<id>/tag` -# send APPEND to `<id>/body` -- a body write ignores its offset, so there -# is no such thing as a partial overwrite by accident -# exec write an `X`/`x` event record, which makes the editor perform the -# action as though nobody had been listening. This is the remote -# control door: it runs pardes builtins and shell commands alike. -# new LOOKUP under `new/`, which is what creates a pane -# del ctl verb `del` -# -# TWO RULES THIS SCRIPT FOLLOWS, AND YOU SHOULD TOO -# -# Always `>>`, never `>`. A plain `>` opens O_TRUNC, which is a setattr with -# size 0 -- a truncate request against a control file. Appending is what every -# writable file here actually wants; the offset is ignored anyway. -# -# `ctl` and `new/ctl` reads carry no trailing newline (acme prints fields, not -# lines), so `read` returns non-zero at end of file even though it has already -# assigned the fields. Hence the `|| :` on those reads. -# -# HOW `exec` RUNS ARBITRARY TEXT -# -# An event write is only `origin type q0 q1` -- no text. The action is named by -# a range of the pane's own text, lowercase type for the tag and uppercase for -# the body. So to run a command that is not on screen yet, this script appends -# it to the tag (a tag write appends to the editable tail), measures where it -# landed, and executes exactly that range. The command text stays visible in -# the tag afterwards, which is also how acme leaves it, and means the user can -# click it again. -# -# USAGE: run with no arguments. -set -u - -self=${0##*/} -mount=${PARDES_FS:-} - -usage() { - cat >&2 <<EOF -$self -- drive pardes through its acme filesystem - -usage: $self [-m mountdir] command [args] - - panes one line per pane: id, dirty flag, body size, tag - body <id> print the pane's text - tag <id> print the pane's tag - send <id> <text...> append a line of text to the pane's body - exec <id> <cmd...> make the editor run <cmd> (builtin or shell command) - new [file] create a pane, optionally loading <file>; prints its id - del <id> delete the pane (refused if it has unsaved changes) - -The mount directory comes from \$PARDES_FS, which pardes sets in every pane -shell when started with --fs, or from -m. \$PARDES_PANE is the id of the pane -a shell is running in, so "$self send \$PARDES_PANE hello" talks to itself. -EOF - exit 2 -} - -die() { printf '%s: %s\n' "$self" "$*" >&2; exit 1; } - -if [ "${1:-}" = "-m" ]; then - [ $# -ge 2 ] || usage - mount=$2 - shift 2 -fi -[ $# -ge 1 ] || usage -[ -n "$mount" ] || die "no mount point: set \$PARDES_FS or pass -m <dir>" -[ -d "$mount" ] || die "$mount is not a directory (has pardes exited?)" - -cmd=$1 -shift - -# Every pane file lives under <mount>/<id>/. Sets $d rather than printing it: -# inside a command substitution `die` would exit only the subshell and the -# caller would sail on with an empty path. Refuses anything that is not a plain -# number, so a typo cannot wander out of the mount. -pane_dir() { - case ${1:-} in - "" | *[!0-9]*) die "expected a pane id (see: $self panes)" ;; - esac - [ -d "$mount/$1" ] || die "no pane $1 (see: $self panes)" - d="$mount/$1" -} - -case $cmd in -panes) - printf '%6s %5s %8s %s\n' ID DIRTY BYTES TAG - while read -r id taglen bodylen isdir dirty tag; do - [ -n "${id:-}" ] || continue - printf '%6s %5s %8s %s\n' \ - "$id" "$([ "${dirty:-0}" = 0 ] && echo - || echo '*')" \ - "${bodylen:-0}" "${tag:-}" - done <"$mount/index" - ;; -body) - pane_dir "${1:-}" - cat -- "$d/body" - ;; -tag) - # A tag read carries no trailing newline, so supply one for the terminal. - pane_dir "${1:-}" - printf '%s\n' "$(cat -- "$d/tag")" - ;; -send) - pane_dir "${1:-}" - shift - [ $# -ge 1 ] || die "send: nothing to send" - printf '%s\n' "$*" >>"$d/body" || die "send: pane went away" - ;; -exec) - pane_dir "${1:-}" - shift - [ $# -ge 1 ] || die "exec: no command" - text=$* - # Where the command will land: byte length of the whole tag, plus the one - # space we prefix so it cannot merge with the word before it. Byte length, - # not character length, because addresses are byte offsets -- ${#text} - # would count characters and mis-address any non-ASCII command. - q0=$(($(wc -c <"$d/tag") + 1)) - q1=$((q0 + $(printf '%s' "$text" | wc -c))) - printf ' %s' "$text" >>"$d/tag" || die "exec: pane went away" - # Lowercase 'x' is a tag exec; origin 'M' reports it as the mouse action - # this stands in for. The editor now runs it. - printf 'Mx%d %d\n' "$q0" "$q1" >>"$d/event" || die "exec: pane refused the event" - ;; -new) - # The lookup itself creates the pane; the ctl read names it. - read -r id _ <"$mount/new/ctl" || : - case ${id:-} in - "" | *[!0-9]*) die "new: unexpected new/ctl contents" ;; - esac - if [ $# -ge 1 ] && [ -n "$1" ]; then - # `name` then `get`: one all-or-nothing ctl write, so the pane is - # never left named after a file it did not load. - printf 'name %s\nget\n' "$1" >>"$mount/$id/ctl" || - die "new: cannot load $1 into pane $id" - fi - printf '%s\n' "$id" - ;; -del) - pane_dir "${1:-}" - printf 'del\n' >>"$d/ctl" || - die "del: pane $1 refused (unsaved changes; save it, or use: $self exec $1 Delete)" - ;; --h | --help | help) - usage - ;; -*) - die "unknown command: $cmd (run with no arguments for usage)" - ;; -esac |