term% cat index.txt OPEN(2) System Calls Manual OPEN(2)
NAME
open - open for reading or writing
SYNOPSIS
open(name, mode)
char *name;
DESCRIPTION
Open opens the file name for reading (if mode is 0), writing (if mode
is 1) or for both reading and writing (if mode is 2). Name is the ad‐
dress of a string of ASCII characters representing a path name, termi‐
nated by a null character.
The file is positioned at the beginning (byte 0). The returned file
descriptor must be used for subsequent calls for other input-output
functions on the file.
SEE ALSO
creat(2), read(2), write(2), dup(2), close(2)
DIAGNOSTICS
The value -1 is returned if the file does not exist, if one of the nec‐
essary directories does not exist or is unreadable, if the file is not
readable (resp. writable), the name is too long, or if too many files
are open.
BUGS
It should be possible to optionally open files for writing with exclu‐
sive use, and to optionally call open without the possibility of hang‐
ing waiting for carrier on communication lines.
OPEN(2)