Hello.
[tested on current git head
f6d4def4e27b13fab174e948b94cd10550d3e10e]
Command substitution doesn't seem to work in $PS4 (used for
xtrace prompt):
$ PS4='$(date +%T)> ' dash -xc :
dash: 1: Syntax error: end of file unexpected (expecting ")")
And with the old syntax:
$ PS4='`date +%T`> ' dash -xc :
> :
And with more than one command:
$ PS4='`date +%T`> ' dash -xc ':;:'
> :
dash doesn't return and seems to go in a forking loop,
presumably because the `date` there triggers another PS4
expansion and so on recursively
If I prevent the recursion with:
--- a/src/eval.c
+++ b/src/eval.c
@@ -776,7 +776,15 @@ evalcommand(union node *cmd, int flags)
int sep;
out = &preverrout;
+
+ /*
+ * reset xflag temporarily for command substitutions performed
+ * upon $PS4 expansion
+ */
+ xflag = 0;
outstr(expandstr(ps4val()), out);
+ xflag = 1;
+
sep = 0;
sep = eprintlist(out, varlist.list, sep);
eprintlist(out, arglist.list, sep);
$ PS4='`date +%T`> ' ./src/dash -xc ':;sleep 1; date'
> :
21:43:47> sleep 1
21:43:48> date
Mon Nov 17 21:43:48 GMT 2014
The command substitution still fails upon the first expansion
only. I quickly gave up trying to find out why as I found the
code there hard to follow.
--
Stephane
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