system, _wsystem
Executes a command.
Important
This API cannot be used in applications that execute in the Windows Runtime. For more information, see CRT functions not supported with /ZW.
int system(
const char *command
);
int _wsystem(
const wchar_t *command
);
Parameters
- command
The command to be executed.
Return Value
If command is NULL and the command interpreter is found, returns a nonzero value. If the command interpreter is not found, returns 0 and sets errno to ENOENT. If command is not NULL, system returns the value that is returned by the command interpreter. It returns the value 0 only if the command interpreter returns the value 0. A return value of – 1 indicates an error, and errno is set to one of the following values:
E2BIG
The argument list (which is system-dependent) is too big.ENOENT
The command interpreter cannot be found.ENOEXEC
The command-interpreter file cannot be executed because the format is not valid.ENOMEM
Not enough memory is available to execute command; or available memory has been corrupted; or a non-valid block exists, which indicates that the process that's making the call was not allocated correctly.
See _doserrno, errno, _sys_errlist, and _sys_nerr for more information about these return codes.
Remarks
The system function passes command to the command interpreter, which executes the string as an operating-system command. system uses the COMSPEC and PATH environment variables to locate the command-interpreter file CMD.exe. If command is NULL, the function just checks whether the command interpreter exists.
You must explicitly flush—by using fflush or _flushall—or close any stream before you call system.
_wsystem is a wide-character version of system; the command argument to _wsystem is a wide-character string. These functions behave identically otherwise.
Generic-Text Routine Mappings
TCHAR.H routine |
_UNICODE & _MBCS not defined |
_MBCS defined |
_UNICODE defined |
|---|---|---|---|
_tsystem |
system |
system |
_wsystem |
Requirements
Routine |
Required header |
|---|---|
system |
<process.h> or <stdlib.h> |
_wsystem |
<process.h> or <stdlib.h> or <wchar.h> |
For additional compatibility information, see Compatibility.
Example
This example uses system to TYPE a text file.
// crt_system.c
#include <process.h>
int main( void )
{
system( "type crt_system.txt" );
}
Input: crt_system.txt
Line one.
Line two.
Output
Line one.
Line two.