Re: getting the return value from a C program

podian,
You are going to want to take a look at least two things:

Inline::C
perldoc -f qx

The first one allows you to in-line C code. The second will allow you to capture the output of an externally called C program as in:

my $foo = qx{ ./external };
[download]

Cheers - L~R

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Re: Re: getting the return value from a C program by graff (Chancellor) on Mar 23, 2004 at 02:50 UTC
perldoc -f qx Um, the OP was asking about capturing the exit status of a C program, which involves using the "system()" call (perldoc -f system) -- not "qx" (aka the backtick operator), ~~which just captures the program's stdout. Also~~ -- OOPS, sorry. I should have read the docs more carefully myself, to see that qx returns stdout and sets $? -- thanks, I'm glad I finally learned that. Anyway (end of update), the more direct reference for qx is "perldoc perlop" (which is where "perldoc -f qx" tells you to look). Another reply below points to the usage of "system()", along with the "$?" variable -- though I prefer using a scalar that has a meaningful name, e.g.: `my $exit_stat = system( "some_shell_command ..." ); printf "Shell_command exit status was %d\n", $exit_stat/256; print "(which means it probably failed)\n" if $exit_stat != 0;` [download] (closing remark to updates: my old habit of using "system()" to get the exit status, vs. using backticks to get stdout data, was simply a matter of being unaware of the $? variable, which is set in either case.)	[reply] [d/l]

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Re: Re: getting the return value from a C program
by graff (Chancellor) on Mar 23, 2004 at 02:50 UTC

perldoc -f qx

Um, the OP was asking about capturing the exit status of a C program, which involves using the "system()" call (perldoc -f system) -- not "qx" (aka the backtick operator), ~~which just captures the program's stdout. Also~~ -- OOPS, sorry. I should have read the docs more carefully myself, to see that qx returns stdout and sets $? -- thanks, I'm glad I finally learned that. Anyway (end of update), the more direct reference for qx is "perldoc perlop" (which is where "perldoc -f qx" tells you to look).

Another reply below points to the usage of "system()", along with the "$?" variable -- though I prefer using a scalar that has a meaningful name, e.g.:

  my $exit_stat = system( "some_shell_command ..." );
  printf "Shell_command exit status was %d\n", $exit_stat/256;
  print "(which means it probably failed)\n" if $exit_stat != 0;
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