Go to the previous, next section.

creat and open

SYNOPSIS

int open(const char *path, int flags);

int open(const char *path, int flags, mode_t mode);

int creat(const char *path, mode_t mode);

PARAMETERS

path: [in] the path of the new file to create.

mode: [in] the new permission mask of the file. It is masked by the umask value: (mode & ~umask).

flags: [in] flags (see description).

DESCRIPTION

open opens an file. The flags parameter must be one of the following:

O_RDONLY

the file is opened for reading.

O_WRONLY

the file is opened for writing.

O_RDWR

the file is opened for both reading and writing.

The following values may be or'ed together and with one of the preceding values:

O_CREAT

create the file if it does not exist.

O_EXCL

used with O_CREAT, if the file exists, the call fails. The test for existence and the creation if the file does not exists is atomic operation according to POSIX.1.

O_NOCTTY

the file will not become the controly tty of the task even if the file is a tty and the task does not have a controling terminal.

O_TRUNC

if the file already exists, truncate its lenght to 0.

O_APPEND

the file is opened for appending. The file pointer is always at the end of the file.

O_NONBLOCK or O_NDELAY

the calls manipulating the file never block.

O_SYNC

the file buffers are always synchronized with the on disk file. The write calls block until the data is completely written on disk. This is not POSIX.1.

RETURN VALUE

On success, a file descriptor for the file is returned. This file descriptor is the lowest numbered unused descriptor. On error, those calls return -1, and errno is set to one of the following values.

• EISDIR: the last component of the path is a directory.
• ETXTBSY: tried to create an already used executable.
• EFAULT, EACCESS, ENAMETOOLONG, ENOENT, ENOTDIR, EMFILE, ENFILE, ENOMEM, EROFS, ELOOP, EEXIST or ENOSPC.

Go to the previous, next section.