How to create an environment variable that is the output of a command












3














How do I create an environment variable that is the result of a specific command?
Specifically, I want an environment variable ($BWD) that is the basename of $PWD



$ cd /home/devel/Autils/lib
$ echo $PWD
/home/devel/Autils/lib
$ # something here to assign BWD
$ echo $BWD
lib









share|improve this question









New contributor




Josh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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    3














    How do I create an environment variable that is the result of a specific command?
    Specifically, I want an environment variable ($BWD) that is the basename of $PWD



    $ cd /home/devel/Autils/lib
    $ echo $PWD
    /home/devel/Autils/lib
    $ # something here to assign BWD
    $ echo $BWD
    lib









    share|improve this question









    New contributor




    Josh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
    Check out our Code of Conduct.























      3












      3








      3







      How do I create an environment variable that is the result of a specific command?
      Specifically, I want an environment variable ($BWD) that is the basename of $PWD



      $ cd /home/devel/Autils/lib
      $ echo $PWD
      /home/devel/Autils/lib
      $ # something here to assign BWD
      $ echo $BWD
      lib









      share|improve this question









      New contributor




      Josh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.











      How do I create an environment variable that is the result of a specific command?
      Specifically, I want an environment variable ($BWD) that is the basename of $PWD



      $ cd /home/devel/Autils/lib
      $ echo $PWD
      /home/devel/Autils/lib
      $ # something here to assign BWD
      $ echo $BWD
      lib






      environment-variables alias






      share|improve this question









      New contributor




      Josh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.











      share|improve this question









      New contributor




      Josh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.









      share|improve this question




      share|improve this question








      edited yesterday









      Jeff Schaller

      39.1k1054125




      39.1k1054125






      New contributor




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      asked yesterday









      JoshJosh

      212




      212




      New contributor




      Josh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.





      New contributor





      Josh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.






      Josh is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.






















          3 Answers
          3






          active

          oldest

          votes


















          9














          In general the sequence foo="$(bar)" will run the command bar and assign the output to the variable.



          e.g.



          % echo $PWD
          /home/sweh
          % BWD="$(basename "$PWD")"
          % echo $BWD
          sweh


          This creates a shell variable. If you want to make it into an environment variable (which can be seen by sub-shells) you can export it.



          e.g.



          export BWD="$(basename "$PWD")"


          However, in this case don't need to run a command, but use shell variable expansion



          BWD=${PWD##*/}





          share|improve this answer



















          • 1




            The next step would be to automatically update BWD when cd is used: cd () { builtin cd "$@" && BWD=${PWD##*/}; }.
            – Kusalananda
            yesterday










          • @Kusalananda trap 'BWD=${PWD##*/}' DEBUG :-)
            – Stephen Harris
            yesterday










          • Depending on the shell used, yes.
            – Kusalananda
            yesterday










          • I'd add quotes to the echo commands as well.
            – kasperd
            yesterday



















          12














          In Bourne-like shells, you create environment variables by marking a shell variable with the export attribute (so it's exported to the environment of the commands that the shell will execute) by using the export builtin utility:



          export BWD


          To assign a value to a shell variable, the syntax is:



          BWD=value


          You can make that value the output of command by using command substitution. In the Bourne shell, that was with the `the-command` syntax, but in modern Bourne-like shells, the preferred way is with $(the-command) instead:



          BWD=$(the-command)


          Usually, you need quotes around command substitutions to prevent split+glob. However, split+glob doesn't occur in assignments to scalar variables, so they're not necessary here.



          The command to get the base name of a file path is the basename command.



          basename "$PWD"


          (the quotes there are necessary as split+glob does occur in arguments to commands).



          That would return the base name of the file stored in $PWD, unless that value starts with -, in which case, YMMV as many basename implementations will treat it as an option. So generally, when passing variable data to command, we use a -- to tell the command that what's after is not to be taken as an option even if it starts with - (here, $PWD should always start with / except in very pathological cases, so it's not strictly needed).



          BWD=$(basename -- "$PWD")
          export BWD


          In modern shells, you can combine both with:



          export BWD="$(basename -- "$PWD")"


          (the quotes are needed in some implementations as we're back in the arguments of commands, though some other implementations do parse the arguments of export like assignments as a special case under some conditions).



          One problem with that approach is if the value of $PWD ends in newline characters (unlikely in practice) as command substitution strips all trailing newline characters. So in:



          mkdir $'foonn'
          cd $'foonn'
          export BWD="$(basename -- "$PWD")"


          $BWD will contain foo instead of $'foonn'.



          Instead, you may want to use shell builtin operators to get that base name. In zsh, that can be done with $PWD:t (t for tail); in all POSIX-like shells (including zsh), that can be done with ${PWD##*/} which removes everything up to the right-most / from the content of $PWD.



          It will give a different result however if $PWD is /. In that case, basename returns / but ${PWD##*/} or $PWD:t expand to the empty string instead. For a directory like /foo/bar/ ($PWD usually doesn't end in / though except for / itself), basename and $PWD:t give bar, while ${PWD##*/} give the empty string again.



          For a variable that dynamically expands to the basename of $PWD, you may use ksh93 and its discipline function:



          ksh93 also has a builtin version of basename provided you have /opt/ast/bin ahead of $PATH. So in ksh93:



          $ PATH=/opt/ast/bin:$PATH
          $ type basename
          basename is a shell builtin version of /opt/ast/bin/basename
          $ BWD.get() { .sh.value=${ basename -- "$PWD"; }; }
          $ cd /var/log
          $ echo "$BWD"
          log
          $ cd /usr/local
          $ echo "$BWD"
          local
          $ export BWD
          $ printenv BWD
          local


          Above, we're using a ksh93-specific form of command substitution: ${ the-command; } which is more efficient in that it doesn't create a subshell environment to run the command.






          share|improve this answer































            3














            You can use the construct foo="$(command)" to return the output of command into the variable foo. So, for your use-case:



            $ BWD="$(basename "$PWD")"





            share|improve this answer



















            • 2




              Or BWD=${PWD##*/}
              – jasonwryan
              yesterday










            • True, but does not answer the underlying actual question asked (to wit: how to assign the output of a command into a variable).
              – DopeGhoti
              yesterday












            • eh? What do you think BWD is? The fact that OP assumes it requires a command does not make it necessary, just misguided.
              – jasonwryan
              yesterday










            • Again, this specific use-case does in fact not require a command, but the question explicitly asked was "how do I get the output of a command into a variable".
              – DopeGhoti
              yesterday










            • OP also explicitly says: "Specifically, I want an environment variable ($BWD) that is the basename of $PWD" Don't selectively quote just because you assume it supports your argument, that is bad faith. OP wanted an outcome, and like many posters, assumed there was only one route there.
              – jasonwryan
              yesterday













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            3 Answers
            3






            active

            oldest

            votes








            3 Answers
            3






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes









            9














            In general the sequence foo="$(bar)" will run the command bar and assign the output to the variable.



            e.g.



            % echo $PWD
            /home/sweh
            % BWD="$(basename "$PWD")"
            % echo $BWD
            sweh


            This creates a shell variable. If you want to make it into an environment variable (which can be seen by sub-shells) you can export it.



            e.g.



            export BWD="$(basename "$PWD")"


            However, in this case don't need to run a command, but use shell variable expansion



            BWD=${PWD##*/}





            share|improve this answer



















            • 1




              The next step would be to automatically update BWD when cd is used: cd () { builtin cd "$@" && BWD=${PWD##*/}; }.
              – Kusalananda
              yesterday










            • @Kusalananda trap 'BWD=${PWD##*/}' DEBUG :-)
              – Stephen Harris
              yesterday










            • Depending on the shell used, yes.
              – Kusalananda
              yesterday










            • I'd add quotes to the echo commands as well.
              – kasperd
              yesterday
















            9














            In general the sequence foo="$(bar)" will run the command bar and assign the output to the variable.



            e.g.



            % echo $PWD
            /home/sweh
            % BWD="$(basename "$PWD")"
            % echo $BWD
            sweh


            This creates a shell variable. If you want to make it into an environment variable (which can be seen by sub-shells) you can export it.



            e.g.



            export BWD="$(basename "$PWD")"


            However, in this case don't need to run a command, but use shell variable expansion



            BWD=${PWD##*/}





            share|improve this answer



















            • 1




              The next step would be to automatically update BWD when cd is used: cd () { builtin cd "$@" && BWD=${PWD##*/}; }.
              – Kusalananda
              yesterday










            • @Kusalananda trap 'BWD=${PWD##*/}' DEBUG :-)
              – Stephen Harris
              yesterday










            • Depending on the shell used, yes.
              – Kusalananda
              yesterday










            • I'd add quotes to the echo commands as well.
              – kasperd
              yesterday














            9












            9








            9






            In general the sequence foo="$(bar)" will run the command bar and assign the output to the variable.



            e.g.



            % echo $PWD
            /home/sweh
            % BWD="$(basename "$PWD")"
            % echo $BWD
            sweh


            This creates a shell variable. If you want to make it into an environment variable (which can be seen by sub-shells) you can export it.



            e.g.



            export BWD="$(basename "$PWD")"


            However, in this case don't need to run a command, but use shell variable expansion



            BWD=${PWD##*/}





            share|improve this answer














            In general the sequence foo="$(bar)" will run the command bar and assign the output to the variable.



            e.g.



            % echo $PWD
            /home/sweh
            % BWD="$(basename "$PWD")"
            % echo $BWD
            sweh


            This creates a shell variable. If you want to make it into an environment variable (which can be seen by sub-shells) you can export it.



            e.g.



            export BWD="$(basename "$PWD")"


            However, in this case don't need to run a command, but use shell variable expansion



            BWD=${PWD##*/}






            share|improve this answer














            share|improve this answer



            share|improve this answer








            edited yesterday









            DopeGhoti

            43.7k55382




            43.7k55382










            answered yesterday









            Stephen HarrisStephen Harris

            25.3k24477




            25.3k24477








            • 1




              The next step would be to automatically update BWD when cd is used: cd () { builtin cd "$@" && BWD=${PWD##*/}; }.
              – Kusalananda
              yesterday










            • @Kusalananda trap 'BWD=${PWD##*/}' DEBUG :-)
              – Stephen Harris
              yesterday










            • Depending on the shell used, yes.
              – Kusalananda
              yesterday










            • I'd add quotes to the echo commands as well.
              – kasperd
              yesterday














            • 1




              The next step would be to automatically update BWD when cd is used: cd () { builtin cd "$@" && BWD=${PWD##*/}; }.
              – Kusalananda
              yesterday










            • @Kusalananda trap 'BWD=${PWD##*/}' DEBUG :-)
              – Stephen Harris
              yesterday










            • Depending on the shell used, yes.
              – Kusalananda
              yesterday










            • I'd add quotes to the echo commands as well.
              – kasperd
              yesterday








            1




            1




            The next step would be to automatically update BWD when cd is used: cd () { builtin cd "$@" && BWD=${PWD##*/}; }.
            – Kusalananda
            yesterday




            The next step would be to automatically update BWD when cd is used: cd () { builtin cd "$@" && BWD=${PWD##*/}; }.
            – Kusalananda
            yesterday












            @Kusalananda trap 'BWD=${PWD##*/}' DEBUG :-)
            – Stephen Harris
            yesterday




            @Kusalananda trap 'BWD=${PWD##*/}' DEBUG :-)
            – Stephen Harris
            yesterday












            Depending on the shell used, yes.
            – Kusalananda
            yesterday




            Depending on the shell used, yes.
            – Kusalananda
            yesterday












            I'd add quotes to the echo commands as well.
            – kasperd
            yesterday




            I'd add quotes to the echo commands as well.
            – kasperd
            yesterday













            12














            In Bourne-like shells, you create environment variables by marking a shell variable with the export attribute (so it's exported to the environment of the commands that the shell will execute) by using the export builtin utility:



            export BWD


            To assign a value to a shell variable, the syntax is:



            BWD=value


            You can make that value the output of command by using command substitution. In the Bourne shell, that was with the `the-command` syntax, but in modern Bourne-like shells, the preferred way is with $(the-command) instead:



            BWD=$(the-command)


            Usually, you need quotes around command substitutions to prevent split+glob. However, split+glob doesn't occur in assignments to scalar variables, so they're not necessary here.



            The command to get the base name of a file path is the basename command.



            basename "$PWD"


            (the quotes there are necessary as split+glob does occur in arguments to commands).



            That would return the base name of the file stored in $PWD, unless that value starts with -, in which case, YMMV as many basename implementations will treat it as an option. So generally, when passing variable data to command, we use a -- to tell the command that what's after is not to be taken as an option even if it starts with - (here, $PWD should always start with / except in very pathological cases, so it's not strictly needed).



            BWD=$(basename -- "$PWD")
            export BWD


            In modern shells, you can combine both with:



            export BWD="$(basename -- "$PWD")"


            (the quotes are needed in some implementations as we're back in the arguments of commands, though some other implementations do parse the arguments of export like assignments as a special case under some conditions).



            One problem with that approach is if the value of $PWD ends in newline characters (unlikely in practice) as command substitution strips all trailing newline characters. So in:



            mkdir $'foonn'
            cd $'foonn'
            export BWD="$(basename -- "$PWD")"


            $BWD will contain foo instead of $'foonn'.



            Instead, you may want to use shell builtin operators to get that base name. In zsh, that can be done with $PWD:t (t for tail); in all POSIX-like shells (including zsh), that can be done with ${PWD##*/} which removes everything up to the right-most / from the content of $PWD.



            It will give a different result however if $PWD is /. In that case, basename returns / but ${PWD##*/} or $PWD:t expand to the empty string instead. For a directory like /foo/bar/ ($PWD usually doesn't end in / though except for / itself), basename and $PWD:t give bar, while ${PWD##*/} give the empty string again.



            For a variable that dynamically expands to the basename of $PWD, you may use ksh93 and its discipline function:



            ksh93 also has a builtin version of basename provided you have /opt/ast/bin ahead of $PATH. So in ksh93:



            $ PATH=/opt/ast/bin:$PATH
            $ type basename
            basename is a shell builtin version of /opt/ast/bin/basename
            $ BWD.get() { .sh.value=${ basename -- "$PWD"; }; }
            $ cd /var/log
            $ echo "$BWD"
            log
            $ cd /usr/local
            $ echo "$BWD"
            local
            $ export BWD
            $ printenv BWD
            local


            Above, we're using a ksh93-specific form of command substitution: ${ the-command; } which is more efficient in that it doesn't create a subshell environment to run the command.






            share|improve this answer




























              12














              In Bourne-like shells, you create environment variables by marking a shell variable with the export attribute (so it's exported to the environment of the commands that the shell will execute) by using the export builtin utility:



              export BWD


              To assign a value to a shell variable, the syntax is:



              BWD=value


              You can make that value the output of command by using command substitution. In the Bourne shell, that was with the `the-command` syntax, but in modern Bourne-like shells, the preferred way is with $(the-command) instead:



              BWD=$(the-command)


              Usually, you need quotes around command substitutions to prevent split+glob. However, split+glob doesn't occur in assignments to scalar variables, so they're not necessary here.



              The command to get the base name of a file path is the basename command.



              basename "$PWD"


              (the quotes there are necessary as split+glob does occur in arguments to commands).



              That would return the base name of the file stored in $PWD, unless that value starts with -, in which case, YMMV as many basename implementations will treat it as an option. So generally, when passing variable data to command, we use a -- to tell the command that what's after is not to be taken as an option even if it starts with - (here, $PWD should always start with / except in very pathological cases, so it's not strictly needed).



              BWD=$(basename -- "$PWD")
              export BWD


              In modern shells, you can combine both with:



              export BWD="$(basename -- "$PWD")"


              (the quotes are needed in some implementations as we're back in the arguments of commands, though some other implementations do parse the arguments of export like assignments as a special case under some conditions).



              One problem with that approach is if the value of $PWD ends in newline characters (unlikely in practice) as command substitution strips all trailing newline characters. So in:



              mkdir $'foonn'
              cd $'foonn'
              export BWD="$(basename -- "$PWD")"


              $BWD will contain foo instead of $'foonn'.



              Instead, you may want to use shell builtin operators to get that base name. In zsh, that can be done with $PWD:t (t for tail); in all POSIX-like shells (including zsh), that can be done with ${PWD##*/} which removes everything up to the right-most / from the content of $PWD.



              It will give a different result however if $PWD is /. In that case, basename returns / but ${PWD##*/} or $PWD:t expand to the empty string instead. For a directory like /foo/bar/ ($PWD usually doesn't end in / though except for / itself), basename and $PWD:t give bar, while ${PWD##*/} give the empty string again.



              For a variable that dynamically expands to the basename of $PWD, you may use ksh93 and its discipline function:



              ksh93 also has a builtin version of basename provided you have /opt/ast/bin ahead of $PATH. So in ksh93:



              $ PATH=/opt/ast/bin:$PATH
              $ type basename
              basename is a shell builtin version of /opt/ast/bin/basename
              $ BWD.get() { .sh.value=${ basename -- "$PWD"; }; }
              $ cd /var/log
              $ echo "$BWD"
              log
              $ cd /usr/local
              $ echo "$BWD"
              local
              $ export BWD
              $ printenv BWD
              local


              Above, we're using a ksh93-specific form of command substitution: ${ the-command; } which is more efficient in that it doesn't create a subshell environment to run the command.






              share|improve this answer


























                12












                12








                12






                In Bourne-like shells, you create environment variables by marking a shell variable with the export attribute (so it's exported to the environment of the commands that the shell will execute) by using the export builtin utility:



                export BWD


                To assign a value to a shell variable, the syntax is:



                BWD=value


                You can make that value the output of command by using command substitution. In the Bourne shell, that was with the `the-command` syntax, but in modern Bourne-like shells, the preferred way is with $(the-command) instead:



                BWD=$(the-command)


                Usually, you need quotes around command substitutions to prevent split+glob. However, split+glob doesn't occur in assignments to scalar variables, so they're not necessary here.



                The command to get the base name of a file path is the basename command.



                basename "$PWD"


                (the quotes there are necessary as split+glob does occur in arguments to commands).



                That would return the base name of the file stored in $PWD, unless that value starts with -, in which case, YMMV as many basename implementations will treat it as an option. So generally, when passing variable data to command, we use a -- to tell the command that what's after is not to be taken as an option even if it starts with - (here, $PWD should always start with / except in very pathological cases, so it's not strictly needed).



                BWD=$(basename -- "$PWD")
                export BWD


                In modern shells, you can combine both with:



                export BWD="$(basename -- "$PWD")"


                (the quotes are needed in some implementations as we're back in the arguments of commands, though some other implementations do parse the arguments of export like assignments as a special case under some conditions).



                One problem with that approach is if the value of $PWD ends in newline characters (unlikely in practice) as command substitution strips all trailing newline characters. So in:



                mkdir $'foonn'
                cd $'foonn'
                export BWD="$(basename -- "$PWD")"


                $BWD will contain foo instead of $'foonn'.



                Instead, you may want to use shell builtin operators to get that base name. In zsh, that can be done with $PWD:t (t for tail); in all POSIX-like shells (including zsh), that can be done with ${PWD##*/} which removes everything up to the right-most / from the content of $PWD.



                It will give a different result however if $PWD is /. In that case, basename returns / but ${PWD##*/} or $PWD:t expand to the empty string instead. For a directory like /foo/bar/ ($PWD usually doesn't end in / though except for / itself), basename and $PWD:t give bar, while ${PWD##*/} give the empty string again.



                For a variable that dynamically expands to the basename of $PWD, you may use ksh93 and its discipline function:



                ksh93 also has a builtin version of basename provided you have /opt/ast/bin ahead of $PATH. So in ksh93:



                $ PATH=/opt/ast/bin:$PATH
                $ type basename
                basename is a shell builtin version of /opt/ast/bin/basename
                $ BWD.get() { .sh.value=${ basename -- "$PWD"; }; }
                $ cd /var/log
                $ echo "$BWD"
                log
                $ cd /usr/local
                $ echo "$BWD"
                local
                $ export BWD
                $ printenv BWD
                local


                Above, we're using a ksh93-specific form of command substitution: ${ the-command; } which is more efficient in that it doesn't create a subshell environment to run the command.






                share|improve this answer














                In Bourne-like shells, you create environment variables by marking a shell variable with the export attribute (so it's exported to the environment of the commands that the shell will execute) by using the export builtin utility:



                export BWD


                To assign a value to a shell variable, the syntax is:



                BWD=value


                You can make that value the output of command by using command substitution. In the Bourne shell, that was with the `the-command` syntax, but in modern Bourne-like shells, the preferred way is with $(the-command) instead:



                BWD=$(the-command)


                Usually, you need quotes around command substitutions to prevent split+glob. However, split+glob doesn't occur in assignments to scalar variables, so they're not necessary here.



                The command to get the base name of a file path is the basename command.



                basename "$PWD"


                (the quotes there are necessary as split+glob does occur in arguments to commands).



                That would return the base name of the file stored in $PWD, unless that value starts with -, in which case, YMMV as many basename implementations will treat it as an option. So generally, when passing variable data to command, we use a -- to tell the command that what's after is not to be taken as an option even if it starts with - (here, $PWD should always start with / except in very pathological cases, so it's not strictly needed).



                BWD=$(basename -- "$PWD")
                export BWD


                In modern shells, you can combine both with:



                export BWD="$(basename -- "$PWD")"


                (the quotes are needed in some implementations as we're back in the arguments of commands, though some other implementations do parse the arguments of export like assignments as a special case under some conditions).



                One problem with that approach is if the value of $PWD ends in newline characters (unlikely in practice) as command substitution strips all trailing newline characters. So in:



                mkdir $'foonn'
                cd $'foonn'
                export BWD="$(basename -- "$PWD")"


                $BWD will contain foo instead of $'foonn'.



                Instead, you may want to use shell builtin operators to get that base name. In zsh, that can be done with $PWD:t (t for tail); in all POSIX-like shells (including zsh), that can be done with ${PWD##*/} which removes everything up to the right-most / from the content of $PWD.



                It will give a different result however if $PWD is /. In that case, basename returns / but ${PWD##*/} or $PWD:t expand to the empty string instead. For a directory like /foo/bar/ ($PWD usually doesn't end in / though except for / itself), basename and $PWD:t give bar, while ${PWD##*/} give the empty string again.



                For a variable that dynamically expands to the basename of $PWD, you may use ksh93 and its discipline function:



                ksh93 also has a builtin version of basename provided you have /opt/ast/bin ahead of $PATH. So in ksh93:



                $ PATH=/opt/ast/bin:$PATH
                $ type basename
                basename is a shell builtin version of /opt/ast/bin/basename
                $ BWD.get() { .sh.value=${ basename -- "$PWD"; }; }
                $ cd /var/log
                $ echo "$BWD"
                log
                $ cd /usr/local
                $ echo "$BWD"
                local
                $ export BWD
                $ printenv BWD
                local


                Above, we're using a ksh93-specific form of command substitution: ${ the-command; } which is more efficient in that it doesn't create a subshell environment to run the command.







                share|improve this answer














                share|improve this answer



                share|improve this answer








                edited yesterday

























                answered yesterday









                Stéphane ChazelasStéphane Chazelas

                300k54564916




                300k54564916























                    3














                    You can use the construct foo="$(command)" to return the output of command into the variable foo. So, for your use-case:



                    $ BWD="$(basename "$PWD")"





                    share|improve this answer



















                    • 2




                      Or BWD=${PWD##*/}
                      – jasonwryan
                      yesterday










                    • True, but does not answer the underlying actual question asked (to wit: how to assign the output of a command into a variable).
                      – DopeGhoti
                      yesterday












                    • eh? What do you think BWD is? The fact that OP assumes it requires a command does not make it necessary, just misguided.
                      – jasonwryan
                      yesterday










                    • Again, this specific use-case does in fact not require a command, but the question explicitly asked was "how do I get the output of a command into a variable".
                      – DopeGhoti
                      yesterday










                    • OP also explicitly says: "Specifically, I want an environment variable ($BWD) that is the basename of $PWD" Don't selectively quote just because you assume it supports your argument, that is bad faith. OP wanted an outcome, and like many posters, assumed there was only one route there.
                      – jasonwryan
                      yesterday


















                    3














                    You can use the construct foo="$(command)" to return the output of command into the variable foo. So, for your use-case:



                    $ BWD="$(basename "$PWD")"





                    share|improve this answer



















                    • 2




                      Or BWD=${PWD##*/}
                      – jasonwryan
                      yesterday










                    • True, but does not answer the underlying actual question asked (to wit: how to assign the output of a command into a variable).
                      – DopeGhoti
                      yesterday












                    • eh? What do you think BWD is? The fact that OP assumes it requires a command does not make it necessary, just misguided.
                      – jasonwryan
                      yesterday










                    • Again, this specific use-case does in fact not require a command, but the question explicitly asked was "how do I get the output of a command into a variable".
                      – DopeGhoti
                      yesterday










                    • OP also explicitly says: "Specifically, I want an environment variable ($BWD) that is the basename of $PWD" Don't selectively quote just because you assume it supports your argument, that is bad faith. OP wanted an outcome, and like many posters, assumed there was only one route there.
                      – jasonwryan
                      yesterday
















                    3












                    3








                    3






                    You can use the construct foo="$(command)" to return the output of command into the variable foo. So, for your use-case:



                    $ BWD="$(basename "$PWD")"





                    share|improve this answer














                    You can use the construct foo="$(command)" to return the output of command into the variable foo. So, for your use-case:



                    $ BWD="$(basename "$PWD")"






                    share|improve this answer














                    share|improve this answer



                    share|improve this answer








                    edited yesterday

























                    answered yesterday









                    DopeGhotiDopeGhoti

                    43.7k55382




                    43.7k55382








                    • 2




                      Or BWD=${PWD##*/}
                      – jasonwryan
                      yesterday










                    • True, but does not answer the underlying actual question asked (to wit: how to assign the output of a command into a variable).
                      – DopeGhoti
                      yesterday












                    • eh? What do you think BWD is? The fact that OP assumes it requires a command does not make it necessary, just misguided.
                      – jasonwryan
                      yesterday










                    • Again, this specific use-case does in fact not require a command, but the question explicitly asked was "how do I get the output of a command into a variable".
                      – DopeGhoti
                      yesterday










                    • OP also explicitly says: "Specifically, I want an environment variable ($BWD) that is the basename of $PWD" Don't selectively quote just because you assume it supports your argument, that is bad faith. OP wanted an outcome, and like many posters, assumed there was only one route there.
                      – jasonwryan
                      yesterday
















                    • 2




                      Or BWD=${PWD##*/}
                      – jasonwryan
                      yesterday










                    • True, but does not answer the underlying actual question asked (to wit: how to assign the output of a command into a variable).
                      – DopeGhoti
                      yesterday












                    • eh? What do you think BWD is? The fact that OP assumes it requires a command does not make it necessary, just misguided.
                      – jasonwryan
                      yesterday










                    • Again, this specific use-case does in fact not require a command, but the question explicitly asked was "how do I get the output of a command into a variable".
                      – DopeGhoti
                      yesterday










                    • OP also explicitly says: "Specifically, I want an environment variable ($BWD) that is the basename of $PWD" Don't selectively quote just because you assume it supports your argument, that is bad faith. OP wanted an outcome, and like many posters, assumed there was only one route there.
                      – jasonwryan
                      yesterday










                    2




                    2




                    Or BWD=${PWD##*/}
                    – jasonwryan
                    yesterday




                    Or BWD=${PWD##*/}
                    – jasonwryan
                    yesterday












                    True, but does not answer the underlying actual question asked (to wit: how to assign the output of a command into a variable).
                    – DopeGhoti
                    yesterday






                    True, but does not answer the underlying actual question asked (to wit: how to assign the output of a command into a variable).
                    – DopeGhoti
                    yesterday














                    eh? What do you think BWD is? The fact that OP assumes it requires a command does not make it necessary, just misguided.
                    – jasonwryan
                    yesterday




                    eh? What do you think BWD is? The fact that OP assumes it requires a command does not make it necessary, just misguided.
                    – jasonwryan
                    yesterday












                    Again, this specific use-case does in fact not require a command, but the question explicitly asked was "how do I get the output of a command into a variable".
                    – DopeGhoti
                    yesterday




                    Again, this specific use-case does in fact not require a command, but the question explicitly asked was "how do I get the output of a command into a variable".
                    – DopeGhoti
                    yesterday












                    OP also explicitly says: "Specifically, I want an environment variable ($BWD) that is the basename of $PWD" Don't selectively quote just because you assume it supports your argument, that is bad faith. OP wanted an outcome, and like many posters, assumed there was only one route there.
                    – jasonwryan
                    yesterday






                    OP also explicitly says: "Specifically, I want an environment variable ($BWD) that is the basename of $PWD" Don't selectively quote just because you assume it supports your argument, that is bad faith. OP wanted an outcome, and like many posters, assumed there was only one route there.
                    – jasonwryan
                    yesterday












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