_creat, _wcreat

Remonter à Io.h - Index

Header File

io.h

Category

Input/output Routines

Prototype

int creat(const char *path, int amode);

int _wcreat(const wchar_t *path, int amode);

Description

Creates a new file or overwrites an existing one.

Remarque :  Remember that a backslash in a path requires '\\'.

creat creates a new file or prepares to rewrite an existing file given by path. amode applies only to newly created files.

A file created with creat is always created in the translation mode specified by the global variable _fmode (O_TEXT or O_BINARY).

If the file exists and the write attribute is set, creat truncates the file to a length of 0 bytes, leaving the file attributes unchanged. If the existing file has the read-only attribute set, the creat call fails and the file remains unchanged.

The creat call examines only the S_IWRITE bit of the access-mode word amode. If that bit is 1, the file can be written to. If the bit is 0, the file is marked as read-only. All other operating system attributes are set to 0.

amode can be one of the following (defined in sys\stat.h):

S_IWRITE	Permission to write
S_IREAD	Permission to read
S_IREAD / S_IWRITE	Permission to read and write (write permission implies read permission)

Return Value

Upon successful completion, _creat returns the new file handle, a nonnegative integer; otherwise, it returns -1.

In the event of error, the global variable errno is set to one of the following:

EACCES	Permission denied
ENOENT	Path or file name not found
EMFILE	Too many open files

Example

 #include <sys\stat.h>
 #include <string.h>
 #include <fcntl.h>
 #include <io.h>
 int main(void)
 {
    int handle;
    char buf[11] = "0123456789";
    /* change the default file mode from text to binary */
    _fmode = O_BINARY;
    /* create a binary file for reading and writing */
    handle = creat("DUMMY.FIL", S_IREAD |S_IWRITE);
    /* write 10 bytes to the file */
    write(handle, buf, strlen(buf));
    /* close the file */
    close(handle);
    return 0;
 }

Portability

	POSIX	Win32	ANSI C	ANSI C++
creat	+	+
_wcreat		NT only