Insert a user defined variable in an alias in Bash












5















I would like to add an alias to a command in my .bashrc file, as in this example:



alias take_row="cat prova.csv_001.txt | awk -v nrow="${nrow}" '{if (NR==nrow) print}'"


But I would like to specify the nrow variable when I launch the command from the terminal. As an example:



take_row 1 --> the script takes the first row



take_row 20 --> the script takes the 20th row



How do I write inside the command something like <command> | <read nrow user input>, etc.?






bash variable alias







share|improve this question





























    5















    I would like to add an alias to a command in my .bashrc file, as in this example:



    alias take_row="cat prova.csv_001.txt | awk -v nrow="${nrow}" '{if (NR==nrow) print}'"


    But I would like to specify the nrow variable when I launch the command from the terminal. As an example:



    take_row 1 --> the script takes the first row



    take_row 20 --> the script takes the 20th row



    How do I write inside the command something like <command> | <read nrow user input>, etc.?






    bash variable alias







    share|improve this question



























      5












      5








      5








      I would like to add an alias to a command in my .bashrc file, as in this example:



      alias take_row="cat prova.csv_001.txt | awk -v nrow="${nrow}" '{if (NR==nrow) print}'"


      But I would like to specify the nrow variable when I launch the command from the terminal. As an example:



      take_row 1 --> the script takes the first row



      take_row 20 --> the script takes the 20th row



      How do I write inside the command something like <command> | <read nrow user input>, etc.?






      bash variable alias







      share|improve this question
















      I would like to add an alias to a command in my .bashrc file, as in this example:



      alias take_row="cat prova.csv_001.txt | awk -v nrow="${nrow}" '{if (NR==nrow) print}'"


      But I would like to specify the nrow variable when I launch the command from the terminal. As an example:



      take_row 1 --> the script takes the first row



      take_row 20 --> the script takes the 20th row



      How do I write inside the command something like <command> | <read nrow user input>, etc.?






      bash variable alias




      bash variable alias






      share|improve this question















      share|improve this question













      share|improve this question




      share|improve this question








      edited 2 hours ago









      wjandrea

      480413




      480413










      asked 10 hours ago









      ccc.nrcccc.nrc

      314




      314






















          1 Answer
          1






          active

          oldest

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          8














          Use a function instead of an alias, in which case you can refer to positional parameters such as $1, etc.



          take_row () {
          
    local nrow=$1
          
    cat prova.csv_001.txt | awk -v nrow="${nrow}" '{if (NR==nrow) print}'
          
}


          In this particular case, you can also address the useless use of cat:



          take_row () {
          
    local nrow=$1
          
    awk -v nrow="${nrow}" '{if (NR==nrow) print}' prova.csv_001.txt
          
}





          share|improve this answer



















          • 1





            Thanks a lot for the suggestions!

            – ccc.nrc
            10 hours ago











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          1 Answer
          1






          active

          oldest

          votes








          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes









          8














          Use a function instead of an alias, in which case you can refer to positional parameters such as $1, etc.



          take_row () {
          
    local nrow=$1
          
    cat prova.csv_001.txt | awk -v nrow="${nrow}" '{if (NR==nrow) print}'
          
}


          In this particular case, you can also address the useless use of cat:



          take_row () {
          
    local nrow=$1
          
    awk -v nrow="${nrow}" '{if (NR==nrow) print}' prova.csv_001.txt
          
}





          share|improve this answer



















          • 1





            Thanks a lot for the suggestions!

            – ccc.nrc
            10 hours ago
















          8














          Use a function instead of an alias, in which case you can refer to positional parameters such as $1, etc.



          take_row () {
          
    local nrow=$1
          
    cat prova.csv_001.txt | awk -v nrow="${nrow}" '{if (NR==nrow) print}'
          
}


          In this particular case, you can also address the useless use of cat:



          take_row () {
          
    local nrow=$1
          
    awk -v nrow="${nrow}" '{if (NR==nrow) print}' prova.csv_001.txt
          
}





          share|improve this answer



















          • 1





            Thanks a lot for the suggestions!

            – ccc.nrc
            10 hours ago














          8












          8








          8







          Use a function instead of an alias, in which case you can refer to positional parameters such as $1, etc.



          take_row () {
          
    local nrow=$1
          
    cat prova.csv_001.txt | awk -v nrow="${nrow}" '{if (NR==nrow) print}'
          
}


          In this particular case, you can also address the useless use of cat:



          take_row () {
          
    local nrow=$1
          
    awk -v nrow="${nrow}" '{if (NR==nrow) print}' prova.csv_001.txt
          
}





          share|improve this answer













          Use a function instead of an alias, in which case you can refer to positional parameters such as $1, etc.



          take_row () {
          
    local nrow=$1
          
    cat prova.csv_001.txt | awk -v nrow="${nrow}" '{if (NR==nrow) print}'
          
}


          In this particular case, you can also address the useless use of cat:



          take_row () {
          
    local nrow=$1
          
    awk -v nrow="${nrow}" '{if (NR==nrow) print}' prova.csv_001.txt
          
}






          share|improve this answer












          share|improve this answer



          share|improve this answer










          answered 10 hours ago









          filbrandenfilbranden

          7,97121038




          7,97121038








          • 1





            Thanks a lot for the suggestions!

            – ccc.nrc
            10 hours ago














          • 1





            Thanks a lot for the suggestions!

            – ccc.nrc
            10 hours ago








          1




          1





          Thanks a lot for the suggestions!

          – ccc.nrc
          10 hours ago





          Thanks a lot for the suggestions!

          – ccc.nrc
          10 hours ago


















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