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authortv <tv@iiso>2011-09-20 15:09:19 +0200
committertv <tv@iiso>2011-09-20 15:09:19 +0200
commitb3a318886407c98b3e91df9173c2d9c2cf195de3 (patch)
tree5fc1dffda896b1a06a15981bc5c977adc41f8e5d /hyper/process
parent08a6dc70d957912c864516ad705c7c724f363b73 (diff)
//hyper spawn: use well known //proc dir
this commit also spawns the command in the current $PWD so spawn ls & co. are viable commands. this commit also sets up a trap for TERM, so dash behaves nicely, again. also we now've got more documentation and debug output [if called with sh -x].
Diffstat (limited to 'hyper/process')
-rwxr-xr-xhyper/process/spawn58
1 files changed, 45 insertions, 13 deletions
diff --git a/hyper/process/spawn b/hyper/process/spawn
index c2b829ca..95854c7d 100755
--- a/hyper/process/spawn
+++ b/hyper/process/spawn
@@ -1,34 +1,61 @@
#! /bin/sh
#
-# spawn [command [argument ...]]
+# [sh -x] spawn [command [argument ...]]
+#
+# export id to create&destroy or reuse the working directory //proc/$id/.
+# this feature is for debug only and marked as deprecated, so don't rely
+# on it too hard.
#
spawn() {
set -euf
- # create and change working directory
- wd=`mktemp -d`
- defer rmdir $wd
+ # establish working subdirectory in //proc. we're mking only
+ # transient dirs, i.e. if we mkdir, then we also defer rmdir.
+ if test -n "${id-}"; then
+ : "using id=$id from env"
+ wd=$pd/$id
+ if ! test -d $wd; then
+ : "make transient $wd/"
+ mkdir $wd
+ defer rmdir $wd
+ elif ! test `ls $wd | wc -l` = 0; then
+ : "$wd/ is not empty!"
+ exit 23
+ else
+ : "reuse existing $wd/"
+ fi
+ else
+ id=`cd $pd && mktemp -d XXXXXXXXXXXXXXXX`
+ wd=$pd/$id
+ defer rmdir $wd
+ : "made transient $wd/"
+ fi
+
+ # change to //proc working directory
+ cwd="$PWD"
cd $wd
+ #defer cd $cwd # no need for this, b/c at that time we're aldeady dead
# create named pipes for the child process's stdio
mkfifo 0 1 2
defer rm 0 1 2
# spawn child process
- (exec 0>&- 1>&- 2>&- 0<>0 1<>1 2<>2 "$@") &
+ ( : "in $PWD/ spawn ${*-"nothing"}"
+ exec 0>&- 1>&- 2>&- 0<>0 1<>1 2<>2
+ cd "$cwd"
+ exec "$@") &
pid=$!
# setup a trap to kill the child process if this (parent) process dies
defer kill $pid
- # write child process's pid
+ # store misc. info.
+ ln -snf $cwd cwd
+ echo $id >id
+ echo $$ >ppid
echo $pid >pid
- defer rm pid
-
- # create dummy directory for easier debugging
- mkdir -vp /tmp/dummy
- ln -vsnf $wd/0 $wd/1 $wd/2 $wd/pid /tmp/dummy/
- defer rm -v /tmp/dummy/0 /tmp/dummy/1 /tmp/dummy/2 /tmp/dummy/pid
+ defer rm cwd id pid ppid
# wait for the child process's
set +e
@@ -65,6 +92,11 @@ cancel() {
defer="`echo "$defer" | grep -Fxv "$*"`"
}
+# setup //proc directory
+pd=/tmp/krebs/proc
+mkdir -p $pd
+test -w $pd
+
# setup deferred execution and spawn command
-trap 'eval "${defer-}"; defer=' EXIT INT
+trap 'eval "${defer-}"; defer=' EXIT INT TERM
spawn "$@"