system - cppreference.com (original) (raw)

| | | | | ----------------------------------- | | | | int system( const char *command ); | | |

Calls the host environment's command processor with the parameter command. Returns an implementation-defined value (usually the value that the invoked program returns).

If command is a null pointer, checks if the host environment has a command processor and returns a nonzero value if and only if the command processor exists.

[edit] Parameters

command	-	character string identifying the command to be run in the command processor. If a null pointer is given, command processor is checked for existence

[edit] Return value

Implementation-defined value. If command is a null pointer, returns a nonzero value if and only if the command processor exists.

[edit] Notes

On POSIX systems, the return value can be decomposed using WEXITSTATUS and WSTOPSIG.

The related POSIX function popen makes the output generated by command available to the caller.

[edit] Example

In this example there is a system call of the unix command date +%A and a system call to (possibly installed) gcc compiler with command-line argument (--version):

#include <stdlib.h> int main(void) { system("date +%A"); system("gcc --version"); }

Possible output:

Wednesday gcc (GCC) 11.2.0 ...

[edit] References