pass char string via system()

zius_oram · #1 (**permalink**) 04-30-2009

hello all
i am trying to pass a argument through system function to a shell script.

Code:

 
#shell script echo.sh to display the string
echo $1

and the c program is.

Code:

 
#include<stdlib.h>
int 
main()
{
  const char *str = "hello all";
  system("sh echo.sh str");
}

the output i get is str and not the string "hello all", what is going wrong here. I want to pass a string argument to a shell script via system function.

Franklin52 · #2 (**permalink**) 04-30-2009

The system command expects a string with a command and str within the command is passed as a literal string, not as a variable. Assign the command to a string before you pass it to the system function, something like:

Code:

#include <stdlib.h>

int main()
{
  const char *str = "echo hello all";
  system(str);
}

zius_oram · #3 (**permalink**) 04-30-2009

thank you for your reply,
actually "hello all" is not fixed, it can be any string coming from a java program which i further pass to shell script, can i do it with system() or i have any other way to send this variable form c to shell script.

Franklin52 · #4 (**permalink**) 04-30-2009

You can use sprintf to format a string with your command and the variable string.

shamrock · #5 (**permalink**) 04-30-2009

The way echo.sh is written it will display just "hello" and not "hello all".

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main()
{
  const char *str = "hello all";
  char cmd[30];
  sprintf(cmd, "./echo.sh %s", str);
  system(cmd);
}

zius_oram · #6 (**permalink**) 04-30-2009

thank you franklin52 and shamrok its working, you dont know but it was the only stage incomplete in my project you helped me a lot......

thankkkkkkkk youuuuuuuu.

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