UNISTD(F) UNIX System V
Name
unistd - file header for symbolic constants
Syntax
#include <unistd.h>
Description
The header file <unistd.h> lists the symbolic constants and
structures not already defined or declared in some other
header file.
/* Symbolic constants for the "access" routine: */
#define R_OK 4 /*Test for Read permission */
#define W_OK 2 /*Test for Write permission */
#define X_OK 1 /*Test for eXecute permission */
#define F_OK 0 /*Test for existence of File */
#define F_ULOCK 0 /*Unlock a previously locked region */
#define F_LOCK 1 /*Lock a region for exclusive use */
#define F_TLOCK 2 /*Test and lock a region for exclusive use */
#define F_TEST 3 /*Test a region for other processes locks */
/*Symbolic constants for the "lseek" routine: */
#define SEEK_SET 0 /* Set file pointer to "offset" */
#define SEEK_CUR 1 /* Set file pointer to current plus "offset" */
#define SEEK_END 2 /* Set file pointer to EOF plus "offset" */
/*Path names:*/
#define GF_PATH "/etc/group"/*Path name of the group file */
#define PF_PATH "/etc/passwd"/*Path name of the passwd file */
Standards Conformance
unistd is conformant with:
The X/Open Portability Guide II of January 1987.
(printed 2/15/90) UNISTD(F)