How can we store the output of a command as an array in Unix shell script?

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I want to store the ouput of a command into an array.
I tried with the below command which I got from a similar question asked here.
Please find below the shell comamnds I used:



#!/bin/ksh

mailx -H >mytest.txt
#awk '/Incident/ print NR;' mytest.txt >lineNum.txt
msgNumbers=$(awk '/Incident/ print NR;' mytest.txt)
echo $msgNumbers


I am able to get the required result directly executing this command in UNIX.
But when I am using the same command within a shell script, I am getting an error:



"syntax error at line 5: `msgNumbers=$' unexpected"


Could someone point out the error in it?










share|improve this question



















  • 1




    What, exactly, are you doing to get that error? It probably doesn't come from the command line above, since there's no mention of msgNumbers in there (and only one line instead of 5). Please edit your question to show the actual command you're running. You can remove the irrelevant parts or any secret data, just make sure to reduce it to a piece of code that actually shows the error.
    – ilkkachu
    Aug 21 at 10:40










  • (Also, I don't think Putty has anything to do with your shell script: it just provides the connection to the shell, it doesn't interpret the code.)
    – ilkkachu
    Aug 21 at 10:41










  • What shell? Not all shells have arrays, and in those that do, the syntax varies between them. See Test for array support by shell
    – Stéphane Chazelas
    Aug 21 at 10:49














up vote
0
down vote

favorite












I want to store the ouput of a command into an array.
I tried with the below command which I got from a similar question asked here.
Please find below the shell comamnds I used:



#!/bin/ksh

mailx -H >mytest.txt
#awk '/Incident/ print NR;' mytest.txt >lineNum.txt
msgNumbers=$(awk '/Incident/ print NR;' mytest.txt)
echo $msgNumbers


I am able to get the required result directly executing this command in UNIX.
But when I am using the same command within a shell script, I am getting an error:



"syntax error at line 5: `msgNumbers=$' unexpected"


Could someone point out the error in it?










share|improve this question



















  • 1




    What, exactly, are you doing to get that error? It probably doesn't come from the command line above, since there's no mention of msgNumbers in there (and only one line instead of 5). Please edit your question to show the actual command you're running. You can remove the irrelevant parts or any secret data, just make sure to reduce it to a piece of code that actually shows the error.
    – ilkkachu
    Aug 21 at 10:40










  • (Also, I don't think Putty has anything to do with your shell script: it just provides the connection to the shell, it doesn't interpret the code.)
    – ilkkachu
    Aug 21 at 10:41










  • What shell? Not all shells have arrays, and in those that do, the syntax varies between them. See Test for array support by shell
    – Stéphane Chazelas
    Aug 21 at 10:49












up vote
0
down vote

favorite









up vote
0
down vote

favorite











I want to store the ouput of a command into an array.
I tried with the below command which I got from a similar question asked here.
Please find below the shell comamnds I used:



#!/bin/ksh

mailx -H >mytest.txt
#awk '/Incident/ print NR;' mytest.txt >lineNum.txt
msgNumbers=$(awk '/Incident/ print NR;' mytest.txt)
echo $msgNumbers


I am able to get the required result directly executing this command in UNIX.
But when I am using the same command within a shell script, I am getting an error:



"syntax error at line 5: `msgNumbers=$' unexpected"


Could someone point out the error in it?










share|improve this question















I want to store the ouput of a command into an array.
I tried with the below command which I got from a similar question asked here.
Please find below the shell comamnds I used:



#!/bin/ksh

mailx -H >mytest.txt
#awk '/Incident/ print NR;' mytest.txt >lineNum.txt
msgNumbers=$(awk '/Incident/ print NR;' mytest.txt)
echo $msgNumbers


I am able to get the required result directly executing this command in UNIX.
But when I am using the same command within a shell script, I am getting an error:



"syntax error at line 5: `msgNumbers=$' unexpected"


Could someone point out the error in it?







shell ksh






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Aug 21 at 10:55









ilkkachu

51.2k678141




51.2k678141










asked Aug 21 at 10:36









Devjith

1




1







  • 1




    What, exactly, are you doing to get that error? It probably doesn't come from the command line above, since there's no mention of msgNumbers in there (and only one line instead of 5). Please edit your question to show the actual command you're running. You can remove the irrelevant parts or any secret data, just make sure to reduce it to a piece of code that actually shows the error.
    – ilkkachu
    Aug 21 at 10:40










  • (Also, I don't think Putty has anything to do with your shell script: it just provides the connection to the shell, it doesn't interpret the code.)
    – ilkkachu
    Aug 21 at 10:41










  • What shell? Not all shells have arrays, and in those that do, the syntax varies between them. See Test for array support by shell
    – Stéphane Chazelas
    Aug 21 at 10:49












  • 1




    What, exactly, are you doing to get that error? It probably doesn't come from the command line above, since there's no mention of msgNumbers in there (and only one line instead of 5). Please edit your question to show the actual command you're running. You can remove the irrelevant parts or any secret data, just make sure to reduce it to a piece of code that actually shows the error.
    – ilkkachu
    Aug 21 at 10:40










  • (Also, I don't think Putty has anything to do with your shell script: it just provides the connection to the shell, it doesn't interpret the code.)
    – ilkkachu
    Aug 21 at 10:41










  • What shell? Not all shells have arrays, and in those that do, the syntax varies between them. See Test for array support by shell
    – Stéphane Chazelas
    Aug 21 at 10:49







1




1




What, exactly, are you doing to get that error? It probably doesn't come from the command line above, since there's no mention of msgNumbers in there (and only one line instead of 5). Please edit your question to show the actual command you're running. You can remove the irrelevant parts or any secret data, just make sure to reduce it to a piece of code that actually shows the error.
– ilkkachu
Aug 21 at 10:40




What, exactly, are you doing to get that error? It probably doesn't come from the command line above, since there's no mention of msgNumbers in there (and only one line instead of 5). Please edit your question to show the actual command you're running. You can remove the irrelevant parts or any secret data, just make sure to reduce it to a piece of code that actually shows the error.
– ilkkachu
Aug 21 at 10:40












(Also, I don't think Putty has anything to do with your shell script: it just provides the connection to the shell, it doesn't interpret the code.)
– ilkkachu
Aug 21 at 10:41




(Also, I don't think Putty has anything to do with your shell script: it just provides the connection to the shell, it doesn't interpret the code.)
– ilkkachu
Aug 21 at 10:41












What shell? Not all shells have arrays, and in those that do, the syntax varies between them. See Test for array support by shell
– Stéphane Chazelas
Aug 21 at 10:49




What shell? Not all shells have arrays, and in those that do, the syntax varies between them. See Test for array support by shell
– Stéphane Chazelas
Aug 21 at 10:49










2 Answers
2






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up vote
0
down vote













That's the error you'd get if you were interpreting that script with the Bourne shell, a very old shell from the 70s hardly used any more these days except maybe on Solaris 10 and older.



So my bet would be that that script is being interpreted by /bin/sh on Solaris 10 or older, not ksh. On Solaris, the standard sh is in /usr/xpg4/bin/sh.



The Bourne shell did not support the $(...) form of command substitution, you had to use `...` instead.



In any case, neither the Bourne shell nor the POSIX sh specification support arrays. To assign an array variable the content of the non-empty lines of the output of a command with Solaris 10's /bin/ksh (which is based on ksh88), you'd need:



set -o noglob
IFS='
'
set -A array -- $(cmd)


(note that ksh88 arrays can't have more than 4096 elements).



And then you display the elements of the array as:



(($#array[@])) && printf '"%s"n' "$array[@]"


If your script has a #!/bin/ksh she-bang, it should be invoked as /path/to/the/script or ksh /path/to/the/script, not sh /path/to/the/script.






share|improve this answer





























    up vote
    0
    down vote













    To assign the separate words that a command outputs to an array in ksh, you may do



    array=( $( mycommand ) )


    This would run mycommand (that awk command in your case), and the output of that command would be split into words on whitespaces (spaces, tabs and newlines by default, which is the contents of the IFS shell variable). The shell would then also perform filename generation ("globbing") on each word, unless set -f was in effect.



    To output these elements, you would use



    printf 'Element: %sn' "$array[@]"


    or



    printf 'Elements: %sn' "$array[*]"


    depending on whether you'd like to output every element individually (the first option), or together, separated by the first character in IFS (the second option). Doing echo $array would only output the first element of the array (and again, since it's unquoted, split it on whitespaces and perform filename generation).



    Or, you could just run your awk command without trying to store the output anywhere (since this would obviously also output the result). This depends on what you want to do with the result of your awk command.






    share|improve this answer






















    • That's ksh93 syntax though, not ksh88. Since the OP's error is that of a Bourne shell, its likely their ksh is a ksh88.
      – Stéphane Chazelas
      Aug 21 at 12:21










    • @StéphaneChazelas Hmm... and I don't have a ksh88 shell available...
      – Kusalananda
      Aug 21 at 12:22










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    2 Answers
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    2 Answers
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    up vote
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    That's the error you'd get if you were interpreting that script with the Bourne shell, a very old shell from the 70s hardly used any more these days except maybe on Solaris 10 and older.



    So my bet would be that that script is being interpreted by /bin/sh on Solaris 10 or older, not ksh. On Solaris, the standard sh is in /usr/xpg4/bin/sh.



    The Bourne shell did not support the $(...) form of command substitution, you had to use `...` instead.



    In any case, neither the Bourne shell nor the POSIX sh specification support arrays. To assign an array variable the content of the non-empty lines of the output of a command with Solaris 10's /bin/ksh (which is based on ksh88), you'd need:



    set -o noglob
    IFS='
    '
    set -A array -- $(cmd)


    (note that ksh88 arrays can't have more than 4096 elements).



    And then you display the elements of the array as:



    (($#array[@])) && printf '"%s"n' "$array[@]"


    If your script has a #!/bin/ksh she-bang, it should be invoked as /path/to/the/script or ksh /path/to/the/script, not sh /path/to/the/script.






    share|improve this answer


























      up vote
      0
      down vote













      That's the error you'd get if you were interpreting that script with the Bourne shell, a very old shell from the 70s hardly used any more these days except maybe on Solaris 10 and older.



      So my bet would be that that script is being interpreted by /bin/sh on Solaris 10 or older, not ksh. On Solaris, the standard sh is in /usr/xpg4/bin/sh.



      The Bourne shell did not support the $(...) form of command substitution, you had to use `...` instead.



      In any case, neither the Bourne shell nor the POSIX sh specification support arrays. To assign an array variable the content of the non-empty lines of the output of a command with Solaris 10's /bin/ksh (which is based on ksh88), you'd need:



      set -o noglob
      IFS='
      '
      set -A array -- $(cmd)


      (note that ksh88 arrays can't have more than 4096 elements).



      And then you display the elements of the array as:



      (($#array[@])) && printf '"%s"n' "$array[@]"


      If your script has a #!/bin/ksh she-bang, it should be invoked as /path/to/the/script or ksh /path/to/the/script, not sh /path/to/the/script.






      share|improve this answer
























        up vote
        0
        down vote










        up vote
        0
        down vote









        That's the error you'd get if you were interpreting that script with the Bourne shell, a very old shell from the 70s hardly used any more these days except maybe on Solaris 10 and older.



        So my bet would be that that script is being interpreted by /bin/sh on Solaris 10 or older, not ksh. On Solaris, the standard sh is in /usr/xpg4/bin/sh.



        The Bourne shell did not support the $(...) form of command substitution, you had to use `...` instead.



        In any case, neither the Bourne shell nor the POSIX sh specification support arrays. To assign an array variable the content of the non-empty lines of the output of a command with Solaris 10's /bin/ksh (which is based on ksh88), you'd need:



        set -o noglob
        IFS='
        '
        set -A array -- $(cmd)


        (note that ksh88 arrays can't have more than 4096 elements).



        And then you display the elements of the array as:



        (($#array[@])) && printf '"%s"n' "$array[@]"


        If your script has a #!/bin/ksh she-bang, it should be invoked as /path/to/the/script or ksh /path/to/the/script, not sh /path/to/the/script.






        share|improve this answer














        That's the error you'd get if you were interpreting that script with the Bourne shell, a very old shell from the 70s hardly used any more these days except maybe on Solaris 10 and older.



        So my bet would be that that script is being interpreted by /bin/sh on Solaris 10 or older, not ksh. On Solaris, the standard sh is in /usr/xpg4/bin/sh.



        The Bourne shell did not support the $(...) form of command substitution, you had to use `...` instead.



        In any case, neither the Bourne shell nor the POSIX sh specification support arrays. To assign an array variable the content of the non-empty lines of the output of a command with Solaris 10's /bin/ksh (which is based on ksh88), you'd need:



        set -o noglob
        IFS='
        '
        set -A array -- $(cmd)


        (note that ksh88 arrays can't have more than 4096 elements).



        And then you display the elements of the array as:



        (($#array[@])) && printf '"%s"n' "$array[@]"


        If your script has a #!/bin/ksh she-bang, it should be invoked as /path/to/the/script or ksh /path/to/the/script, not sh /path/to/the/script.







        share|improve this answer














        share|improve this answer



        share|improve this answer








        edited Aug 21 at 13:20

























        answered Aug 21 at 12:17









        Stéphane Chazelas

        285k53525864




        285k53525864






















            up vote
            0
            down vote













            To assign the separate words that a command outputs to an array in ksh, you may do



            array=( $( mycommand ) )


            This would run mycommand (that awk command in your case), and the output of that command would be split into words on whitespaces (spaces, tabs and newlines by default, which is the contents of the IFS shell variable). The shell would then also perform filename generation ("globbing") on each word, unless set -f was in effect.



            To output these elements, you would use



            printf 'Element: %sn' "$array[@]"


            or



            printf 'Elements: %sn' "$array[*]"


            depending on whether you'd like to output every element individually (the first option), or together, separated by the first character in IFS (the second option). Doing echo $array would only output the first element of the array (and again, since it's unquoted, split it on whitespaces and perform filename generation).



            Or, you could just run your awk command without trying to store the output anywhere (since this would obviously also output the result). This depends on what you want to do with the result of your awk command.






            share|improve this answer






















            • That's ksh93 syntax though, not ksh88. Since the OP's error is that of a Bourne shell, its likely their ksh is a ksh88.
              – Stéphane Chazelas
              Aug 21 at 12:21










            • @StéphaneChazelas Hmm... and I don't have a ksh88 shell available...
              – Kusalananda
              Aug 21 at 12:22














            up vote
            0
            down vote













            To assign the separate words that a command outputs to an array in ksh, you may do



            array=( $( mycommand ) )


            This would run mycommand (that awk command in your case), and the output of that command would be split into words on whitespaces (spaces, tabs and newlines by default, which is the contents of the IFS shell variable). The shell would then also perform filename generation ("globbing") on each word, unless set -f was in effect.



            To output these elements, you would use



            printf 'Element: %sn' "$array[@]"


            or



            printf 'Elements: %sn' "$array[*]"


            depending on whether you'd like to output every element individually (the first option), or together, separated by the first character in IFS (the second option). Doing echo $array would only output the first element of the array (and again, since it's unquoted, split it on whitespaces and perform filename generation).



            Or, you could just run your awk command without trying to store the output anywhere (since this would obviously also output the result). This depends on what you want to do with the result of your awk command.






            share|improve this answer






















            • That's ksh93 syntax though, not ksh88. Since the OP's error is that of a Bourne shell, its likely their ksh is a ksh88.
              – Stéphane Chazelas
              Aug 21 at 12:21










            • @StéphaneChazelas Hmm... and I don't have a ksh88 shell available...
              – Kusalananda
              Aug 21 at 12:22












            up vote
            0
            down vote










            up vote
            0
            down vote









            To assign the separate words that a command outputs to an array in ksh, you may do



            array=( $( mycommand ) )


            This would run mycommand (that awk command in your case), and the output of that command would be split into words on whitespaces (spaces, tabs and newlines by default, which is the contents of the IFS shell variable). The shell would then also perform filename generation ("globbing") on each word, unless set -f was in effect.



            To output these elements, you would use



            printf 'Element: %sn' "$array[@]"


            or



            printf 'Elements: %sn' "$array[*]"


            depending on whether you'd like to output every element individually (the first option), or together, separated by the first character in IFS (the second option). Doing echo $array would only output the first element of the array (and again, since it's unquoted, split it on whitespaces and perform filename generation).



            Or, you could just run your awk command without trying to store the output anywhere (since this would obviously also output the result). This depends on what you want to do with the result of your awk command.






            share|improve this answer














            To assign the separate words that a command outputs to an array in ksh, you may do



            array=( $( mycommand ) )


            This would run mycommand (that awk command in your case), and the output of that command would be split into words on whitespaces (spaces, tabs and newlines by default, which is the contents of the IFS shell variable). The shell would then also perform filename generation ("globbing") on each word, unless set -f was in effect.



            To output these elements, you would use



            printf 'Element: %sn' "$array[@]"


            or



            printf 'Elements: %sn' "$array[*]"


            depending on whether you'd like to output every element individually (the first option), or together, separated by the first character in IFS (the second option). Doing echo $array would only output the first element of the array (and again, since it's unquoted, split it on whitespaces and perform filename generation).



            Or, you could just run your awk command without trying to store the output anywhere (since this would obviously also output the result). This depends on what you want to do with the result of your awk command.







            share|improve this answer














            share|improve this answer



            share|improve this answer








            edited Sep 18 at 16:21









            Isaac

            7,1311835




            7,1311835










            answered Aug 21 at 12:18









            Kusalananda

            107k14209329




            107k14209329











            • That's ksh93 syntax though, not ksh88. Since the OP's error is that of a Bourne shell, its likely their ksh is a ksh88.
              – Stéphane Chazelas
              Aug 21 at 12:21










            • @StéphaneChazelas Hmm... and I don't have a ksh88 shell available...
              – Kusalananda
              Aug 21 at 12:22
















            • That's ksh93 syntax though, not ksh88. Since the OP's error is that of a Bourne shell, its likely their ksh is a ksh88.
              – Stéphane Chazelas
              Aug 21 at 12:21










            • @StéphaneChazelas Hmm... and I don't have a ksh88 shell available...
              – Kusalananda
              Aug 21 at 12:22















            That's ksh93 syntax though, not ksh88. Since the OP's error is that of a Bourne shell, its likely their ksh is a ksh88.
            – Stéphane Chazelas
            Aug 21 at 12:21




            That's ksh93 syntax though, not ksh88. Since the OP's error is that of a Bourne shell, its likely their ksh is a ksh88.
            – Stéphane Chazelas
            Aug 21 at 12:21












            @StéphaneChazelas Hmm... and I don't have a ksh88 shell available...
            – Kusalananda
            Aug 21 at 12:22




            @StéphaneChazelas Hmm... and I don't have a ksh88 shell available...
            – Kusalananda
            Aug 21 at 12:22

















             

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