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Posted by Justin Fletcher on November 11, 2007, 10:41 am
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>>
>> [snip]
>>
>> > if I print "$1\n",
>> > the file prints just fine. But, if I do something like print "$1 after
>> > \n", the whole output is messed up. If I print "before $1\n", nothing
>> > prints at all. If I print "before $1 after\n", only after prints.
>>
>> not really sure, but could be a rogue "\r" in $1,
> There
> is a rogue carriage return (0xd) in the string
> Is there something I can do to deal with this
> situation?
Repair the corrupted file:
perl -p -i -e 'tr/\r//d' bad_file
--
Tad McClellan SGML consulting
tadmc@augustmail.com Perl programming
Fort Worth, Texas
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Posted by Martijn Lievaart on November 11, 2007, 3:40 pm
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>>
>> [snip]
>>
>> > if I print "$1\n",
>> > the file prints just fine. But, if I do something like print "$1 after
>> > \n", the whole output is messed up. If I print "before $1\n", nothing
>> > prints at all. If I print "before $1 after\n", only after prints.
>>
>> not really sure, but could be a rogue "\r" in $1,
> There
> is a rogue carriage return (0xd) in the string
> Is there something I can do to deal with this
> situation?
Repair the corrupted file:
perl -p -i -e 'tr/\r//d' bad_file
--
Tad McClellan SGML consulting
tadmc@augustmail.com Perl programming
Fort Worth, Texas
|
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Posted by Ben Morrow on November 11, 2007, 7:21 pm
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>> [snip]
>>
>> > if I print "$1\n",
>> > the file prints just fine. But, if I do something like print "$1 after
>> > \n", the whole output is messed up. If I print "before $1\n", nothing
>> > prints at all. If I print "before $1 after\n", only after prints.
>>
>> not really sure, but could be a rogue "\r" in $1,
> There
> is a rogue carriage return (0xd) in the string
> Is there something I can do to deal with this
> situation?
Repair the corrupted file:
perl -p -i -e 'tr/\r//d' bad_file
--
Tad McClellan SGML consulting
tadmc@augustmail.com Perl programming
Fort Worth, Texas
|
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Posted by xhoster on November 11, 2007, 10:30 pm
Please log in for more thread options >>
>> [snip]
>>
>> > if I print "$1\n",
>> > the file prints just fine. But, if I do something like print "$1 after
>> > \n", the whole output is messed up. If I print "before $1\n", nothing
>> > prints at all. If I print "before $1 after\n", only after prints.
>>
>> not really sure, but could be a rogue "\r" in $1,
> There
> is a rogue carriage return (0xd) in the string
> Is there something I can do to deal with this
> situation?
Repair the corrupted file:
perl -p -i -e 'tr/\r//d' bad_file
--
Tad McClellan SGML consulting
tadmc@augustmail.com Perl programming
Fort Worth, Texas
|
|
Posted by Ben Morrow on November 12, 2007, 9:34 am
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Quoth xhoster@gmail.com:
> >
> > I'm having a problem trying to get a simple program to respond the way
> > that I expect. The basic premise is thus :
> >
> > 1. Fork a child.
> > 2. Sleep for a while.
> > 3. Do other stuff.
> >
> > This seems pretty simple, and I have a SIGCHLD handler which will catch
> > my forked process if it exits. I thought everything was fine. Then I
> > found that is I press ctrl-Z to suspend the parent whilst I'm running the
> > program and then background it, it hangs.
>
> I find that this only occurs if I hit ctrl-Z from the keyboard. If I
> send the process the TSTP signal via some other means, it doesn't happen.
> I know that shells often respond to ctrl-Z, ctrl-C, etc, by sending signals
> to entire process groups, rather than just the main process. I don't
> exactly how this leads to the observed phenomena, though.
SIGCHLD is sent to the parent whenever a child changes status. So when
you press ctrl-Z, the whole process group is signalled, the child is
stopped, and the parent gets a SIGCHLD. When the process group is
resumed (bg or fg) the parent gets another SIGCHLD: since it hasn't
responded to the first yet (because it was stopped), this is not
usually apparent.
If the OP really doesn't want SIGCHLDs when a child stops, he can
install the signal handler explicitly with sigaction and SA_NOCLDSTOP
(under systems which support that). Since one must assume that any
number of children may have exitted when handling SIGCHLD anyway,
including 0 in 'any number' is generally easier.
Ben
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