addmntent
GETMNTENT(3) Linux Programmer's Manual GETMNTENT(3)
NAME
getmntent, setmntent, addmntent, endmntent, hasmntopt - get file system
descriptor file entry
SYNOPSIS
#include <stdio.h>
#include <mntent.h>
FILE *setmntent(const char *filename, const char *type);
struct mntent *getmntent(FILE *filep);
int addmntent(FILE *filep, const struct mntent *mnt);
int endmntent(FILE *filep);
char *hasmntopt(const struct mntent *mnt, const char *opt);
DESCRIPTION
These routines are used to access the file system description file
/etc/fstab and the mounted file system description file /etc/mtab.
The setmntent() function opens the file system description file filep
and returns a file pointer which can be used by getmntent(). The argu-
ment type is the type of access required and can take the same values
as the mode argument of fopen(3).
The getmntent() function reads the next line from the file system
description file filep and returns a pointer to a structure containing
the broken out fields from a line in the file. The pointer points to a
static area of memory which is overwritten by subsequent calls to getm-
ntent().
The addmntent() function adds the mntent structure mnt to the end of
the open file filep.
The endmntent() function closes the file system description file filep.
The hasmntopt() function scans the mnt_opts field (see below) of the
mntent structure mnt for a substring that matches opt. See <mntent.h>
for valid mount options.
The mntent structure is defined in <mntent.h> as follows:
struct mntent {
char *mnt_fsname; /* name of mounted file system */
char *mnt_dir; /* file system path prefix */
char *mnt_type; /* mount type (see mntent.h) */
char *mnt_opts; /* mount options (see mntent.h) */
int mnt_freq; /* dump frequency in days */
int mnt_passno; /* pass number on parallel fsck */
};
RETURN VALUE
The getmntent() function returns a pointer to the mntent structure or
NULL on failure.
The addmntent() function returns 0 on success and 1 on failure.
The endmntent() function always returns 1.
The hasmntopt() function returns the address of the substring if a
match is found and NULL otherwise.
FILES
/etc/fstab file system description file
/etc/mtab mounted file system description file
CONFORMING TO
SunOS 4.1.3.
NOTES
SysV also has a getmntent() function but the calling sequence differs,
and the returned structure is different. Under SysV /etc/mnttab is
used. BSD 4.4 and Digital Unix have a routine getmntinfo(), a wrapper
around the system call getfsstat().
SEE ALSO
fopen(3), fstab(5)
1993-06-27 GETMNTENT(3)