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Sqrt issue in bash

guillermo -  
lami20j Posted messages 21506 Registration date   Status Moderator, Security Contributor Last intervention   -
Hello,
right now, I am working on a bash program and I need to calculate a square root.
For that, I am using the command sqrt:
to calculate the square root of the variable "$a" and store it in the variable "$rac", I do the following: $rac = sqrt($a)

But when I run the script, I get the following message:
./essai2.sh: line 14: Syntax error near unexpected token « ( »
./essai2.sh: line 14: '$rac = sqrt($a)'

Thank you in advance.

Configuration: Linux / Firefox 3.6.13

2 answers

  1.
    KarCAroum Posted messages 298 Status Member 91
     
    Good evening,
    rac=$(bc -l <<< "sqrt($a)") (corrected)
    2
    1. zipe31 Posted messages 34620 Registration date   Status Contributor Last intervention   6 501
       
      Hi,

      A variable in bash is declared without the "$" sign (dollar) and without spaces before or after the "=" sign (equal) ;-(( 

      rac=$(bc -l <<<"sqrt($a)")
      0
    2. KarCAroum Posted messages 298 Status Member 91
       
      certainly but the essential is bc -l <<<"sqrt($a)"
      0
    3. zipe31 Posted messages 34620 Registration date   Status Contributor Last intervention   6 501
       
      Sure, but the comment was just in the interest of our friend guillermo ;-))
      1
    4. KarCAroum Posted messages 298 Status Member 91
       
      she is fully justified
      0
    5. lami20j Posted messages 21506 Registration date   Status Moderator, Security Contributor Last intervention   3 571
       
      Hello,

      @zipe31

      It reminds me of a message ;-)
      0
  2. guillermo
     
    Thank you very much, it works. But I would like to understand why we have to use: "bc -l".
    0
    1. lami20j Posted messages 21506 Registration date   Status Moderator, Security Contributor Last intervention   3 571
       
      Re,

      Try it without -l and you'll see
      Look at man bc too
      0