getmntent(3C)

NAME

     getmntent, getmntany,  getextmntent,  hasmntopt,  putmntent,
     resetmnttab - get mounted device information

SYNOPSIS

     #include <stdio.h>
     #include <sys/mnttab.h>

     int getmntent(FILE *fp, struct mnttab *mp);

     int getmntany(FILE *fp, struct  mnttab  *mp,  struct  mnttab
     *mpref);

     int getextmntent(FILE *fp, struct extmnttab *mp, int len);

     char *hasmntopt(struct mnttab *mnt, char *opt);

     int putmntent(FILE *iop, struct mnttab *mp);

     void resetmnttab(FILE *fp);

DESCRIPTION

  getmntent() and getmntany()
     The getmntent() and getmntany() functions each fill  in  the
     structure  pointed  to by mp with the broken-out fields of a
     line in the mnttab file. Each line read from the  file  con-
     tains   a   mnttab   structure,  which  is  defined  in  the
     <sys/mnttab.h> header. The structure contains the  following
     members,  which  correspond  to the broken-out fields from a
     line in /etc/mnttab (see mnttab(4)).

     char   *mnt_special;     /* name of mounted resource */
     char   *mnt_mountp;      /* mount point */
     char   *mnt_fstype;      /* type of file system mounted */
     char   *mnt_mntopts;     /* options for this mount */
     char   *mnt_time;        /* time file system mounted */

     Each getmntent() call causes a new line to be read from  the
     mnttab  file.  Successive  calls  can  be used to search the
     entire list. The  getmntany()  function  searches  the  file
     referenced  by  fp  until a match is found between a line in
     the file and mpref. A match occurs if all  non-null  entries
     in  mpref  match  the corresponding fields in the file. Note
     that these functions do not open, close, or rewind the file.

  getextmntent()
     The getextmntent() function is an extended  version  of  the
     getmntent() function that returns, in addition to the infor-
     mation that getmntent() returns, the major and minor  number
     of  the  mounted  resource  to  which  the  line  in  mnttab
     corresponds. The getextmntent() function also fills  in  the
     extmntent  structure  defined  in the <sys/mnttab.h> header.
     For getextmntent() to function properly, it must be notified
     when  the  mnttab  file has been reopened or rewound since a
     previous getextmntent() call.  This notification  is  accom-
     plished  by  calling  resetmnttab().  Otherwise,  it behaves
     exactly as getmntent() described above

     The data pointed to by  the  mnttab  structure  members  are
     stored  in  a  static  area  and  must be copied to be saved
     between successive calls.

  hasmntopt()
     The hasmntopt() function scans the mnt_mntopts member of the
     mnttab  structure  mnt  for a substring that matches opt. It
     returns the address of the substring if a  match  is  found;
     otherwise  it  returns 0. Substrings are delimited by commas
     and the end of the mnt_mntopts string.

  putmntent()
     The putmntent() function is obsolete and no longer  has  any
     effect.  Entries  appear  in  mnttab  as  a side effect of a
     mount(2) call. The function name is still defined for  tran-
     sition purposes.

  resetmnttab()
     The resetmnttab() function notifies getextmntent() to reload
     from  the  kernel the device information that corresponds to
     the new snapshot of the mnttab information (see  mnttab(4)).
     Subsequent   getextmntent()   calls   then   return  correct
     extmnttab information. This function should be called  when-
     ever  the  mnttab  file is either rewound or closed and reo-
     pened before any calls are made to getextmntent().

RETURN VALUES

  getmntent() and getmntany()
     If the next entry is successfully read by getmntent()  or  a
     match  is  found with getmntany(), 0 is returned.  If an EOF
     is encountered on reading, these functions return -1. If  an
     error  is  encountered,  a value greater than 0 is returned.
     The following error values are defined in <sys/mnttab.h>:

     MNT_TOOLONG
           A line in the file exceeded the internal  buffer  size
           of MNT_LINE_MAX.

     MNT_TOOMANY
           A line in the file contains too many fields.

     MNT_TOOFEW
           A line in the file contains too few fields.

  hasmntopt()

     Upon successful completion, hasmntopt() returns the  address
     of  the substring if a match is found. Otherwise, it returns
     0.

  putmntent()
     The putmntent() is obsolete and always returns -1.

ATTRIBUTES

     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | MT-Level                    | Safe                        |
    |_____________________________|_____________________________|

SEE ALSO

     mount(2), mnttab(4), attributes(5)