Museum

 unistd(FP)                     6 January 1993                     unistd(FP)


 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:
    X/Open Portability Guide, Issue 3, 1989.