tags:

views:

42

answers:

2

At the shell, I enter a single-quote and then carriage return and then a series of lines and then another single-quote:

root@aim:/root > '
> @stat = lstat($ARGV[0]);
> if (!@stat) {
if (@stat = lstat($ARGV[0]);) {
> print "nil\n";
> exit 0;
>  }
> '

However, if you notice the interpreted output from the shell:

bash: 
@stat = lstat($ARGV[0]);
if (@stat = lstat($ARGV[0]);) {
print "nil\n";
exit 0;
 }
: command not found
root@aim:/root > uname -a
IRIX64 aim 6.5 04091957 IP27
root@aim:/root > echo $0
-bash
root@aim:/root > 

You notice that !@stat gets converted to @stat = lstat($ARGV[0]);

How should the following shell program be written so that the perl program within it gets interpreted literally?

tramp_perl_file_attributes () {
\perl -e '
@stat = lstat($ARGV[0]);
if (!@stat) {
   print "nil\n";
   exit 0;
}
if (($stat[2] & 0170000) == 0120000)
{
   $type = readlink($ARGV[0]);
   $type = "\"$type\"";
}
elsif (($stat[2] & 0170000) == 040000)
{
   $type = "t";
}
else
{
   $type = "nil"
};
$uid = ($ARGV[1] eq "integer") ? $stat[4] : "\"" . getpwuid($stat[4]) . "\"";
$gid = ($ARGV[1] eq "integer") ? $stat[5] : "\"" . getgrgid($stat[5]) . "\"";
printf(
   "(%s %u %s %s (%u %u) (%u %u) (%u %u) %u.0 %u t (%u . %u) -1)\n",
   $type,
   $stat[3],
   $uid,
   $gid,
   $stat[8] >> 16 & 0xffff,
   $stat[8] & 0xffff,
   $stat[9] >> 16 & 0xffff,
   $stat[9] & 0xffff,
   $stat[10] >> 16 & 0xffff,
   $stat[10] & 0xffff,
   $stat[7],
   $stat[2],
   $stat[1] >> 16 & 0xffff,
   $stat[1] & 0xffff
);' "$1" "$2"
}
+1  A: 

Escape the ! or disable history expansion (with set +H) while you type the command.

For some reason, ! is expanded from the history (!! gets expanded to the last command you typed on the command line) which shouldn't happen between single quotes.

Aaron Digulla
From bash manual: "Only backslash (\) and single quotes can quote the history expansion character."
Roman Cheplyaka
That may be so but looking at the problem the OP has, you can clearly see that !@ got expanded from the history. I don't know *why* (because I agree that the single quotes should prevent that) but it happens. I've updated my answer to stress this more clearly.
Aaron Digulla
A: 

Works perfectly here with bash 4.1.5 under Debian Linux. What version of bash do you have on IRIX? Maybe it's old and buggy? As a workaround, you can use here-docs:

tramp_perl_file_attributes () {
perl - "$1" "$2" <<'EOF'
@stat = lstat($ARGV[0]);
if (!@stat) {
   print "nil\n";
   exit 0;
}
if (($stat[2] & 0170000) == 0120000)
{
   $type = readlink($ARGV[0]);
   $type = "\"$type\"";
}
elsif (($stat[2] & 0170000) == 040000)
{
   $type = "t";
}
else
{
   $type = "nil"
};
$uid = ($ARGV[1] eq "integer") ? $stat[4] : "\"" . getpwuid($stat[4]) . "\"";
$gid = ($ARGV[1] eq "integer") ? $stat[5] : "\"" . getgrgid($stat[5]) . "\"";
printf(
   "(%s %u %s %s (%u %u) (%u %u) (%u %u) %u.0 %u t (%u . %u) -1)\n",
   $type,
   $stat[3],
   $uid,
   $gid,
   $stat[8] >> 16 & 0xffff,
   $stat[8] & 0xffff,
   $stat[9] >> 16 & 0xffff,
   $stat[9] & 0xffff,
   $stat[10] >> 16 & 0xffff,
   $stat[10] & 0xffff,
   $stat[7],
   $stat[2],
   $stat[1] >> 16 & 0xffff,
   $stat[1] & 0xffff
);
EOF
}
Roman Cheplyaka