Computer Science
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 descrip-
tion file /etc/fstab and the mounted file system descrip-
tion 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 argument 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 getmntent().
The addmntent() function adds the mntent structure mnt to
the end of the open file filep.
The endmntent() function closes the file system descrip-
tion 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 sub-
string if a match is found and NULL otherwise.
FILES
/etc/fstab file system description file
/etc/mtab mounted file system description file
CONFORMING TO
BSD 4.3
SEE ALSO
fopen(3), fstab(5)
June 27, 1993 1
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