How to detect an error at the beginning of a pipeline?











up vote
0
down vote

favorite












In my script I need to work with the exit status of the non-last command of a pipeline:



 do_real_work 2>&1 | tee real_work.log


To my surprise, $? contains the exit code of the tee. Indeed, the following command:



false 2>&1 | tee /dev/null ; echo $?


outputs 0. Surprise, because the csh's (almost) equivalent



false |& tee /dev/null ; echo $status


prints 1.



How do I get the exit code of the non-last command of the most recent pipeline?










share|improve this question


























    up vote
    0
    down vote

    favorite












    In my script I need to work with the exit status of the non-last command of a pipeline:



     do_real_work 2>&1 | tee real_work.log


    To my surprise, $? contains the exit code of the tee. Indeed, the following command:



    false 2>&1 | tee /dev/null ; echo $?


    outputs 0. Surprise, because the csh's (almost) equivalent



    false |& tee /dev/null ; echo $status


    prints 1.



    How do I get the exit code of the non-last command of the most recent pipeline?










    share|improve this question
























      up vote
      0
      down vote

      favorite









      up vote
      0
      down vote

      favorite











      In my script I need to work with the exit status of the non-last command of a pipeline:



       do_real_work 2>&1 | tee real_work.log


      To my surprise, $? contains the exit code of the tee. Indeed, the following command:



      false 2>&1 | tee /dev/null ; echo $?


      outputs 0. Surprise, because the csh's (almost) equivalent



      false |& tee /dev/null ; echo $status


      prints 1.



      How do I get the exit code of the non-last command of the most recent pipeline?










      share|improve this question













      In my script I need to work with the exit status of the non-last command of a pipeline:



       do_real_work 2>&1 | tee real_work.log


      To my surprise, $? contains the exit code of the tee. Indeed, the following command:



      false 2>&1 | tee /dev/null ; echo $?


      outputs 0. Surprise, because the csh's (almost) equivalent



      false |& tee /dev/null ; echo $status


      prints 1.



      How do I get the exit code of the non-last command of the most recent pipeline?







      sh pipeline






      share|improve this question













      share|improve this question











      share|improve this question




      share|improve this question










      asked Nov 15 at 0:14









      Mikhail T.

      9831129




      9831129
























          1 Answer
          1






          active

          oldest

          votes

















          up vote
          1
          down vote



          accepted










          Bash has set -o pipefail which uses the first non-zero exit code (if any) as the exit code of a pipeline.



          POSIX shell doesn't have such a feature AFAIK. You could work around that with a different approach:



          tail -F -n0 real_work.log &
          do_real_work > real_work.log 2>&1
          kill $!


          That is, start following the as yet non-existing file before running the command, and kill the process after running the command.






          share|improve this answer





















            Your Answer






            StackExchange.ifUsing("editor", function () {
            StackExchange.using("externalEditor", function () {
            StackExchange.using("snippets", function () {
            StackExchange.snippets.init();
            });
            });
            }, "code-snippets");

            StackExchange.ready(function() {
            var channelOptions = {
            tags: "".split(" "),
            id: "1"
            };
            initTagRenderer("".split(" "), "".split(" "), channelOptions);

            StackExchange.using("externalEditor", function() {
            // Have to fire editor after snippets, if snippets enabled
            if (StackExchange.settings.snippets.snippetsEnabled) {
            StackExchange.using("snippets", function() {
            createEditor();
            });
            }
            else {
            createEditor();
            }
            });

            function createEditor() {
            StackExchange.prepareEditor({
            heartbeatType: 'answer',
            convertImagesToLinks: true,
            noModals: true,
            showLowRepImageUploadWarning: true,
            reputationToPostImages: 10,
            bindNavPrevention: true,
            postfix: "",
            imageUploader: {
            brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
            contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
            allowUrls: true
            },
            onDemand: true,
            discardSelector: ".discard-answer"
            ,immediatelyShowMarkdownHelp:true
            });


            }
            });














            draft saved

            draft discarded


















            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53310682%2fhow-to-detect-an-error-at-the-beginning-of-a-pipeline%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown

























            1 Answer
            1






            active

            oldest

            votes








            1 Answer
            1






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes








            up vote
            1
            down vote



            accepted










            Bash has set -o pipefail which uses the first non-zero exit code (if any) as the exit code of a pipeline.



            POSIX shell doesn't have such a feature AFAIK. You could work around that with a different approach:



            tail -F -n0 real_work.log &
            do_real_work > real_work.log 2>&1
            kill $!


            That is, start following the as yet non-existing file before running the command, and kill the process after running the command.






            share|improve this answer

























              up vote
              1
              down vote



              accepted










              Bash has set -o pipefail which uses the first non-zero exit code (if any) as the exit code of a pipeline.



              POSIX shell doesn't have such a feature AFAIK. You could work around that with a different approach:



              tail -F -n0 real_work.log &
              do_real_work > real_work.log 2>&1
              kill $!


              That is, start following the as yet non-existing file before running the command, and kill the process after running the command.






              share|improve this answer























                up vote
                1
                down vote



                accepted







                up vote
                1
                down vote



                accepted






                Bash has set -o pipefail which uses the first non-zero exit code (if any) as the exit code of a pipeline.



                POSIX shell doesn't have such a feature AFAIK. You could work around that with a different approach:



                tail -F -n0 real_work.log &
                do_real_work > real_work.log 2>&1
                kill $!


                That is, start following the as yet non-existing file before running the command, and kill the process after running the command.






                share|improve this answer












                Bash has set -o pipefail which uses the first non-zero exit code (if any) as the exit code of a pipeline.



                POSIX shell doesn't have such a feature AFAIK. You could work around that with a different approach:



                tail -F -n0 real_work.log &
                do_real_work > real_work.log 2>&1
                kill $!


                That is, start following the as yet non-existing file before running the command, and kill the process after running the command.







                share|improve this answer












                share|improve this answer



                share|improve this answer










                answered Nov 15 at 0:35









                l0b0

                33.1k1583144




                33.1k1583144






























                    draft saved

                    draft discarded




















































                    Thanks for contributing an answer to Stack Overflow!


                    • Please be sure to answer the question. Provide details and share your research!

                    But avoid



                    • Asking for help, clarification, or responding to other answers.

                    • Making statements based on opinion; back them up with references or personal experience.


                    To learn more, see our tips on writing great answers.





                    Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


                    Please pay close attention to the following guidance:


                    • Please be sure to answer the question. Provide details and share your research!

                    But avoid



                    • Asking for help, clarification, or responding to other answers.

                    • Making statements based on opinion; back them up with references or personal experience.


                    To learn more, see our tips on writing great answers.




                    draft saved


                    draft discarded














                    StackExchange.ready(
                    function () {
                    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53310682%2fhow-to-detect-an-error-at-the-beginning-of-a-pipeline%23new-answer', 'question_page');
                    }
                    );

                    Post as a guest















                    Required, but never shown





















































                    Required, but never shown














                    Required, but never shown












                    Required, but never shown







                    Required, but never shown

































                    Required, but never shown














                    Required, but never shown












                    Required, but never shown







                    Required, but never shown







                    Popular posts from this blog

                    How to change which sound is reproduced for terminal bell?

                    Can I use Tabulator js library in my java Spring + Thymeleaf project?

                    Title Spacing in Bjornstrup Chapter, Removing Chapter Number From Contents