HP-UX Reference (11i v1 00/12) - 3 Library Functions A-M (vol 6)

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STANDARD Printed by: Nora Chuang [nchuang] STANDARD

/build/1111/BRICK/man3/!!!intro.3c

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getmntent(3X) getmntent(3X)

optional in /etc/fstab and /etc/mnttab . In the supplied structure, such

missing character pointer ﬁelds are set to NULL and missing integer ﬁelds are set to

−1 for mnt_freq and mnt_passno . If the integer ﬁeld for mnt_time is miss-

ing, it is set to 0.

getmntent_r() Returns a -1 on error or EOF, or if the supplied buffer is of insufﬁcient length. If the

operation is successful, 0 is returned.

addmntent() Returns 1 on error.

delmntent() Returns -1 on error. Sets errno to EINVAL if stream or mnt are null pointers, or if

both mnt_fsname and mnt_dir in mntent structure mnt are null pointers. Sets

errno to EBADF if stream has been opened for read (r), append (a) or write (w). If the

operation is successful, returns the number of entries deleted from the ﬁle. When no

entries are matched, delmntent returns 0 and does not set errno.

endmntent() Returns 1, and unlocks the ﬁle if it was locked by setmntent() .

EXAMPLES

The following code deletes an entry:

struct mntent mnt_entry;

FILE *fp;

int retval = NOT_DELETED;

mnt_entry.mnt_fsname = "/dev/vg00/lvol7";

mnt_entry.mnt_dir = "/disk7";

if ((fp = setmntent(MNT_MNTTAB, "r+")) != NULL) {

if (delmntent(fp, &mnt_entry) > 0)

retval = DELETED;

(void)endmntent(fp);

}

return(retval);

APPLICATION USAGE

Data integrity is not guaranteed when reading the mntent data because setmntent() does not lock

the ﬁle when opening it with read only permission.

Programs should expect that the ﬁle accessed by these APIs may be write locked by another process

because setmntent() attempts to establish an exclusive write lock when opening it for write/update.

Use of a text editor to manipulate the ﬁle accessed by these APIs is not supported.

MULTITHREAD USAGE

setmntent() and endmntent() are safe for per process locking, but are not safe for locking from

multiple threads of the same process. getmntent() , addmntent() , delmntent() , and

hasmntent() are safe to be called from multi-threaded applications. setmntent() , getmntent() ,

addmntent() , delmntent() , hasmntent() , and endmntent() are not async-signal safe, and

they are not safe to be called by a child process after fork() but before exec().

addmntent() is

async-cancel safe, however

setmntent() , getmntent() , delmntent() , hasmntent() , and

endmntent() are not async-cancel safe.

AUTHOR

addmntent() , endmntent() , getmntent(), hasmntopt() , and setmntent() were

developed by The University of California, Berkeley, Sun Microsystems, Inc., and HP. delmntent()

was developed by HP.

FILES

/etc/fstab

/etc/mnttab