GETMNTENT

getmntent, setmntent, addmntent, endmntent, hasmntopt ? get file system descriptor file entry

#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);

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 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 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 */

};

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.

/etc/fstab          file system description file
/etc/mtab           mounted file system description file

BSD 4.3

fopen(3), fstab(5)