how to execute command and get it's result?

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  • sonet
    #1

    how to execute command and get it's result?

    in perl
    we can execute command and get result(command line stdout) by

    $a=`cmdline parameter`;
    print $a;

    in c
    system('cmdline parameter');
    but i can not get the result (command line stdout).

    in c++?
    =============== =============== =============== ========
    have any standard method do this job?


    Tags: None
    • Ian Collins
      #2
      Re: how to execute command and get it's result?

      sonet wrote:
      in perl
      we can execute command and get result(command line stdout) by
      >
      $a=`cmdline parameter`;
      print $a;
      >
      in c
      system('cmdline parameter');
      but i can not get the result (command line stdout).
      >
      Direct the output to a file and read the file.

      --
      Ian Collins.

        Comment

        • Spiros Bousbouras
          #3
          Re: how to execute command and get it's result?

          On 21 Jun, 05:59, Ian Collins <ian-n...@hotmail.co mwrote:
          sonet wrote:
          in perl
          we can execute command and get result(command line stdout) by
          >
          $a=`cmdline parameter`;
          print $a;
          >
          in c
          system('cmdline parameter');
          but i can not get the result (command line stdout).
          >
          Direct the output to a file and read the file.
          This of course assuming that whatever interprereter
          system() invokes supports redirections.

            Comment

            • sonet
              #4
              Re: how to execute command and get it's result?

              Yes!
              I can use system systemcall and direct the output to a file
              and read the file. May be it is like.

              system("cmdline parameter file");

              But if the program is cgi,we need generate a random filename.
              It may be a solution,but the method look very stupid.
              Have any other smart method to read the stdout from other command line?


              "Spiros Bousbouras" <spibou@gmail.c om>
              1182404061.2659 73.200270@w5g20 00...legro ups.com...
              On 21 Jun, 05:59, Ian Collins <ian-n...@hotmail.co mwrote:
              >sonet wrote:
              in perl
              we can execute command and get result(command line stdout) by
              >>
              $a=`cmdline parameter`;
              print $a;
              >>
              in c
              system('cmdline parameter');
              but i can not get the result (command line stdout).
              >>
              >Direct the output to a file and read the file.
              >
              This of course assuming that whatever interprereter
              system() invokes supports redirections.
              >

                Comment

                • Ian Collins
                  #5
                  Re: how to execute command and get it's result?

                  sonet wrote:

                  Please don't top-post.
                  >
                  "Spiros Bousbouras" <spibou@gmail.c om>
                  1182404061.2659 73.200270@w5g20 00...legro ups.com...
                  >On 21 Jun, 05:59, Ian Collins <ian-n...@hotmail.co mwrote:
                  >>sonet wrote:
                  >>>in perl
                  >>>we can execute command and get result(command line stdout) by
                  >>>$a=`cmdlin e parameter`;
                  >>>print $a;
                  >>>in c
                  >>>system('cmdl ine parameter');
                  >>>but i can not get the result (command line stdout).
                  >>Direct the output to a file and read the file.
                  >This of course assuming that whatever interprereter
                  >system() invokes supports redirections.
                  >>
                  Yes!
                  I can use system systemcall and direct the output to a file
                  and read the file. May be it is like.
                  >
                  system("cmdline parameter file");
                  >
                  But if the program is cgi,we need generate a random filename.
                  It may be a solution,but the method look very stupid.
                  Have any other smart method to read the stdout from other command
                  line?
                  >
                  There will be a better way, but it will be platform specific, so try the
                  question on a group dedicated to your OS.

                  --
                  Ian Collins.

                    Comment

                    • !truth
                      #6
                      Re: how to execute command and get it's result?

                      On 6 21 , 2 38 , Ian Collins <ian-n...@hotmail.co mwrote:
                      sonet wrote:
                      >
                      Please don't top-post.
                      >
                      >
                      >
                      >
                      >
                      "Spiros Bousbouras" <spi...@gmail.c om>
                      1182404061.2659 73.200...@w5g20 00hsg.googlegro ups.com...
                      On 21 Jun, 05:59, Ian Collins <ian-n...@hotmail.co mwrote:
                      >sonet wrote:
                      >>in perl
                      >>we can execute command and get result(command line stdout) by
                      >>$a=`cmdline parameter`;
                      >>print $a;
                      >>in c
                      >>system('cmdli ne parameter');
                      >>but i can not get the result (command line stdout).
                      >Direct the output to a file and read the file.
                      This of course assuming that whatever interprereter
                      system() invokes supports redirections.
                      >
                      Yes!
                      I can use system systemcall and direct the output to a file
                      and read the file. May be it is like.
                      >
                      system("cmdline parameter file");
                      >
                      But if the program is cgi,we need generate a random filename.
                      It may be a solution,but the method look very stupid.
                      Have any other smart method to read the stdout from other command
                      line?
                      >
                      There will be a better way, but it will be platform specific, so try the
                      question on a group dedicated to your OS.
                      >
                      --
                      Ian Collins.- -
                      >
                      - -
                      maybe you can use 'popen'

                        Comment

                        • Ian Collins
                          #7
                          Re: how to execute command and get it's result?

                          !truth wrote:
                          On 6 21 , 2 38 , Ian Collins <ian-n...@hotmail.co mwrote:
                          >sonet wrote:
                          >>"Spiros Bousbouras" <spi...@gmail.c om>
                          >>1182404061.26 5973.200...@w5g 2000hsg.googleg roups.com...
                          >>>On 21 Jun, 05:59, Ian Collins <ian-n...@hotmail.co mwrote:
                          >>>>sonet wrote:
                          >>>>>in perl
                          >>>>>we can execute command and get result(command line stdout) by
                          >>>>>$a=`cmdlin e parameter`;
                          >>>>>print $a;
                          >>>>>in c
                          >>>>>system('cm dline parameter');
                          >>>>>but i can not get the result (command line stdout).
                          >>>>Direct the output to a file and read the file.
                          >>>This of course assuming that whatever interprereter
                          >>>system() invokes supports redirections.
                          >>Yes!
                          >>I can use system systemcall and direct the output to a file
                          >>and read the file. May be it is like.
                          >>system("cmdli ne parameter file");
                          >>But if the program is cgi,we need generate a random filename.
                          >>It may be a solution,but the method look very stupid.
                          >>Have any other smart method to read the stdout from other command
                          >>line?
                          >There will be a better way, but it will be platform specific, so try the
                          >question on a group dedicated to your OS.
                          >>
                          *Please* don't quote signatures.
                          >
                          maybe you can use 'popen'
                          >
                          Not if you OS doesn't have popen(), that's why I suggested a platform
                          specific group.

                          --
                          Ian Collins.

                            Comment

                            • SM Ryan
                              #8
                              Re: how to execute command and get it's result?

                              "sonet" <sonet.all@msa. hinet.netwrote:
                              # in perl
                              # we can execute command and get result(command line stdout) by
                              #
                              # $a=`cmdline parameter`;
                              # print $a;
                              #
                              # in c
                              # system('cmdline parameter');
                              # but i can not get the result (command line stdout).
                              #
                              # in c++?
                              # =============== =============== =============== ========
                              # have any standard method do this job?

                              Since the C standard doesn't even interpret the string in the
                              system() call, you're out of luck with the C standard.

                              Other standards provide additional methods, such as the
                              popen in unix and some other systems. Unix also provides
                              additional ways to redirect stdin, stdout, and stderr
                              separately.

                              Decide what systems you're willing to abandon and code
                              to that standard.

                              --
                              SM Ryan http://www.rawbw.com/~wyrmwif/
                              Who's leading this mob?

                                Comment

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