creat, _wcreat

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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.

Note: 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