The Perl exec and system commands have two argument formats:

1. single string argument (invokes a shell and interprets the string as a shell command). 

system( "ls *.txt" );

[download]

2. a list of more than one element (invokes the list elements as a program, without shell interpolation). 

my @list=("someprog", "progarg1", "progarg2");
system( @list );

[download]

In the first format, SIGINT cannot be captured in the return status of the system() call, but in the second format, if a signal is sent to the program, it is passed into the Perl script through the system() return status.

I need to capture SIGINT, but I need to use system commands with piping, and also redirecting the output to a tmpfile.

I've searched for some CPAN module that might already do this but haven't found anything. Something like this: 

$sysret = system("prog1 file1 | filter -v $version > $tmpfile 2>&1");
$syssig = $sysret & 0x7f;

[download]

Splitting the pipe, and redirection operators into separate list elements, and then using the list format, doesn't work: the operators are not interpreted properly.

Any suggestions??

Thanks!
-cadphile

In reply to SIGINT in system() with shell metachars by cadphile

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.