How can I run a function from a script in command line

Question

I have a script that has some functions   Can I run one of the function directly from command line   Something like this   myScript sh func

User · Answer

I have a situation where I need a function from bash script which must not be executed before (e.g. by source) and the problem with @$ is that myScript.sh is then run twice, it seems... So I've come up with the idea to get the function out with sed:

sed -n "/^func ()/,/^}/p" myScript.sh

And to execute it at the time I need it, I put it in a file and use source:

sed -n "/^func ()/,/^}/p" myScript.sh > func.sh; source func.sh; rm func.sh

User · Answer

Edit  WARNING - seems this doesn t work in all cases  but works well on many public scripts   If you have a bash script called  control  and inside it you have a function called  build    function build                 Then you can call it like this  from the directory where it is      control build   If it s inside another folder  that would make it   another folder control build   If your file is called  control sh   that would accordingly make the function callable like this     control sh build

User · Answer

you can call function from command line argument like below  function irfan     echo  Irfan khan  date hostname   function config     ifconfig echo  hey     1   once you function end put  1 to accept argument  let say above code is saved in fun sh to run function   fun sh irfan  amp    fun sh config

User · Answer

The following command first registers the function in the context  then calls it       myScript sh  amp  amp  function name

User · Answer

Solved post but I d like to mention my preferred solution  Namely  define a generic one-liner script eval func sh      bin bash source  1  amp  amp  shift  amp  amp    a    Then call any function within any script via     eval func sh  lt any script gt   lt any function gt   lt any args gt       An issue I ran into with the accepted solution is that when sourcing my function-containing script within another script  the arguments of the latter would be evaluated by the former  causing an error

User · Answer

Using case     bin bash  fun1          echo  run function1                  amp  amp  echo  options         fun2          echo  run function2                  amp  amp  echo  options         case  1 in     fun1        exit       fun2        exit   esac  fun1 fun2   This script will run functions fun1 and fun2 but if you start it with option fun1 or fun2 it ll only run given function with args if provided  and exit  Usage      test  run function1 run function2      test fun2 a b c run function2 options  a b c

User · Answer

If the script only defines the functions and does nothing else  you can first execute the script within the context of the current shell using the source or   command and then simply call the function   See help source for more information

User · Answer

Well  while the other answers are right - you can certainly do something else  if you have access to the bash script  you can modify it  and simply place at the end the special parameter      - which will expand to the arguments of the command line you specify  and since it s  alone  the shell will try to call them verbatim  and here you could specify the function name as the first argument  Example       cat test sh testA       echo  TEST A  1      testB       echo  TEST B  2               bash test sh   bash test sh testA TEST A    bash test sh testA arg1 arg2 TEST A arg1   bash test sh testB arg1 arg2 TEST B arg2   For polish  you can first verify that the command exists and is a function     Check if the function exists  bash specific  if declare -f   1   gt   dev null then     call arguments verbatim        else     Show a helpful error   echo    1  is not a known function name   gt  amp 2   exit 1 fi

User · Answer

Briefly  no   You can import all of the functions in the script into your environment with source  help source for details   which will then allow you to call them  This also has the effect of executing the script  so take care   There is no way to call a function from a shell script as if it were a shared library

[linux] How can I run a function from a script in command line?

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