| system | function |
int system ( const char * command ); |
<cstdlib> |
Execute system command
Invokes the command processor to execute a command. Once the command execution has terminated, the processor gives the control back to the program, returning an int value, whose interpretation is system-dependent.
The function call also be used with NULL as argument to check whether a command processor exists.
Parameters
- command
- C string containing the system command to be executed.
Return Value
The value returned when the argument passed is not NULL, depends on the running environment specifications. In many systems, 0 is used to indicate that the command was succesfully executed and other values to indicate some sort of error.When the argument passed is NULL, the function returns a nonzero value if the command processor is available, and zero otherwise.
Portability
The behavior and return value are platform-dependent.Example
/* system example : DIR */ #include <stdio.h> #include <stdlib.h> int main () { int i; printf ("Checking if processor is available..."); if (system(NULL)) puts ("Ok"); else exit (1); printf ("Executing command DIR...\n"); i=system ("dir"); printf ("The value returned was: %d.\n",i); return 0; } |
See also
| exit | Terminate calling process (function) |