GETMNTENT(3)               Linux Programmer's Manual              GETMNTENT(3)

       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 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-

       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

       SunOS 4.1.3.

       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().

       fopen(3), fstab(5)

                                  1993-06-27                      GETMNTENT(3)