How do I check if a file exists by trimming a given string?











up vote
0
down vote

favorite












Lets say I have the following files Foo-Bar1.mp3 Foo-Bar2.jpg Foo-Bar1.mp3 Foo-Bar1.mp4
I want to download them so they are in a url like www.example.com/1/Foo%20-Bar1.mp3
I want to cut the URL so that I can use it to check if the file exists before I download it



if [ ! -f Foo-Bar1.mp3 ]; then
#Download it
fi`









share|improve this question


























    up vote
    0
    down vote

    favorite












    Lets say I have the following files Foo-Bar1.mp3 Foo-Bar2.jpg Foo-Bar1.mp3 Foo-Bar1.mp4
    I want to download them so they are in a url like www.example.com/1/Foo%20-Bar1.mp3
    I want to cut the URL so that I can use it to check if the file exists before I download it



    if [ ! -f Foo-Bar1.mp3 ]; then
    #Download it
    fi`









    share|improve this question
























      up vote
      0
      down vote

      favorite









      up vote
      0
      down vote

      favorite











      Lets say I have the following files Foo-Bar1.mp3 Foo-Bar2.jpg Foo-Bar1.mp3 Foo-Bar1.mp4
      I want to download them so they are in a url like www.example.com/1/Foo%20-Bar1.mp3
      I want to cut the URL so that I can use it to check if the file exists before I download it



      if [ ! -f Foo-Bar1.mp3 ]; then
      #Download it
      fi`









      share|improve this question













      Lets say I have the following files Foo-Bar1.mp3 Foo-Bar2.jpg Foo-Bar1.mp3 Foo-Bar1.mp4
      I want to download them so they are in a url like www.example.com/1/Foo%20-Bar1.mp3
      I want to cut the URL so that I can use it to check if the file exists before I download it



      if [ ! -f Foo-Bar1.mp3 ]; then
      #Download it
      fi`






      bash terminal






      share|improve this question













      share|improve this question











      share|improve this question




      share|improve this question










      asked Nov 22 at 15:40









      Bret Joseph

      409




      409
























          1 Answer
          1






          active

          oldest

          votes

















          up vote
          2
          down vote



          accepted










          You can use parameter expansion to accomplish this :



           $ url='www.example.com/1/Foo%20-Bar1.mp3'
          $ name=${url##*/}
          $ echo $name
          Foo%20-Bar1.mp3
          $ echo ${name/%20/}
          Foo-Bar1.mp3


          Regards!



          Note - As noted by @oguzismail you can use echo -e ${name//%/x} to decode each url character.






          share|improve this answer



















          • 3




            You can use echo -e ${name//%/\x} to decode every % encoded char.
            – oguzismail
            Nov 22 at 15:57








          • 1




            Nice! Thanks for the tip. Im adding your contribution.
            – Matias Barrios
            Nov 22 at 16:00











          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',
          autoActivateHeartbeat: false,
          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%2f53434308%2fhow-do-i-check-if-a-file-exists-by-trimming-a-given-string%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
          2
          down vote



          accepted










          You can use parameter expansion to accomplish this :



           $ url='www.example.com/1/Foo%20-Bar1.mp3'
          $ name=${url##*/}
          $ echo $name
          Foo%20-Bar1.mp3
          $ echo ${name/%20/}
          Foo-Bar1.mp3


          Regards!



          Note - As noted by @oguzismail you can use echo -e ${name//%/x} to decode each url character.






          share|improve this answer



















          • 3




            You can use echo -e ${name//%/\x} to decode every % encoded char.
            – oguzismail
            Nov 22 at 15:57








          • 1




            Nice! Thanks for the tip. Im adding your contribution.
            – Matias Barrios
            Nov 22 at 16:00















          up vote
          2
          down vote



          accepted










          You can use parameter expansion to accomplish this :



           $ url='www.example.com/1/Foo%20-Bar1.mp3'
          $ name=${url##*/}
          $ echo $name
          Foo%20-Bar1.mp3
          $ echo ${name/%20/}
          Foo-Bar1.mp3


          Regards!



          Note - As noted by @oguzismail you can use echo -e ${name//%/x} to decode each url character.






          share|improve this answer



















          • 3




            You can use echo -e ${name//%/\x} to decode every % encoded char.
            – oguzismail
            Nov 22 at 15:57








          • 1




            Nice! Thanks for the tip. Im adding your contribution.
            – Matias Barrios
            Nov 22 at 16:00













          up vote
          2
          down vote



          accepted







          up vote
          2
          down vote



          accepted






          You can use parameter expansion to accomplish this :



           $ url='www.example.com/1/Foo%20-Bar1.mp3'
          $ name=${url##*/}
          $ echo $name
          Foo%20-Bar1.mp3
          $ echo ${name/%20/}
          Foo-Bar1.mp3


          Regards!



          Note - As noted by @oguzismail you can use echo -e ${name//%/x} to decode each url character.






          share|improve this answer














          You can use parameter expansion to accomplish this :



           $ url='www.example.com/1/Foo%20-Bar1.mp3'
          $ name=${url##*/}
          $ echo $name
          Foo%20-Bar1.mp3
          $ echo ${name/%20/}
          Foo-Bar1.mp3


          Regards!



          Note - As noted by @oguzismail you can use echo -e ${name//%/x} to decode each url character.







          share|improve this answer














          share|improve this answer



          share|improve this answer








          edited Nov 22 at 16:01

























          answered Nov 22 at 15:54









          Matias Barrios

          1,497316




          1,497316








          • 3




            You can use echo -e ${name//%/\x} to decode every % encoded char.
            – oguzismail
            Nov 22 at 15:57








          • 1




            Nice! Thanks for the tip. Im adding your contribution.
            – Matias Barrios
            Nov 22 at 16:00














          • 3




            You can use echo -e ${name//%/\x} to decode every % encoded char.
            – oguzismail
            Nov 22 at 15:57








          • 1




            Nice! Thanks for the tip. Im adding your contribution.
            – Matias Barrios
            Nov 22 at 16:00








          3




          3




          You can use echo -e ${name//%/\x} to decode every % encoded char.
          – oguzismail
          Nov 22 at 15:57






          You can use echo -e ${name//%/\x} to decode every % encoded char.
          – oguzismail
          Nov 22 at 15:57






          1




          1




          Nice! Thanks for the tip. Im adding your contribution.
          – Matias Barrios
          Nov 22 at 16:00




          Nice! Thanks for the tip. Im adding your contribution.
          – Matias Barrios
          Nov 22 at 16:00


















          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%2f53434308%2fhow-do-i-check-if-a-file-exists-by-trimming-a-given-string%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

          Lallio

          Futebolista

          Jornalista