hasmntopt(3c)

1getmntent(3C)            Standard C Library Functions            getmntent(3C)
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NAME

6       getmntent, getmntany, getextmntent, hasmntopt, putmntent, resetmnttab -
7       get mounted device information
8

SYNOPSIS

10       #include <stdio.h>
11       #include <sys/mnttab.h>
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13       int getmntent(FILE *fp, struct mnttab *mp);
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15
16       int getmntany(FILE *fp, struct mnttab *mp, struct mnttab *mpref);
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19       int getextmntent(FILE *fp, struct extmnttab *mp, int len);
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21
22       char *hasmntopt(struct mnttab *mnt, char *opt);
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24
25       int putmntent(FILE *iop, struct mnttab *mp);
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27
28       void resetmnttab(FILE *fp);
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30

DESCRIPTION

32   getmntent() and getmntany()
33       The getmntent() and getmntany() functions each fill  in  the  structure
34       pointed  to  by  mp  with the broken-out fields of a line in the mnttab
35       file. Each line read from the file contains a mnttab  structure,  which
36       is  defined  in  the  <sys/mnttab.h> header. The structure contains the
37       following members, which correspond to the  broken-out  fields  from  a
38       line in /etc/mnttab (see mnttab(4)).
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40         char   *mnt_special;     /* name of mounted resource */
41         char   *mnt_mountp;      /* mount point */
42         char   *mnt_fstype;      /* type of file system mounted */
43         char   *mnt_mntopts;     /* options for this mount */
44         char   *mnt_time;        /* time file system mounted */
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47
48       Fields  with  no  actual  content in /etc/mnttab are represented in the
49       file as "-". To clearly distinguish empty fields, getmntent()  set  the
50       corresponding field in mp to NULL.
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52
53       Each  getmntent()  call  causes  a  new line to be read from the mnttab
54       file. Successive calls can be used to search the entire list. The getm‐
55       ntany()  function  searches  the file referenced by fp until a match is
56       found between a line in the file and mpref. A match occurs if all  non-
57       null entries in mpref match the corresponding fields in the file. These
58       functions do not open, close, or rewind the file.
59
60   getextmntent()
61       The getextmntent() function is an extended version of  the  getmntent()
62       function  that returns, in addition to the information that getmntent()
63       returns, the major and minor number of the mounted  resource  to  which
64       the  line in mnttab corresponds. The getextmntent() function also fills
65       in the extmntent structure defined in the <sys/mnttab.h>  header.   For
66       getextmntent()  to function properly, it must be notified when the mnt‐
67       tab file has been reopened or rewound since a  previous  getextmntent()
68       call.  This notification is accomplished by calling resetmnttab(). Oth‐
69       erwise, it behaves exactly as getmntent() described above
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71
72       The data pointed to by the mnttab structure members  are  stored  in  a
73       static area and must be copied to be saved between successive calls.
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75   hasmntopt()
76       The  hasmntopt()  function  scans  the mnt_mntopts member of the mnttab
77       structure mnt for a substring that matches opt. It returns the  address
78       of  the  substring  if  a  match is found; otherwise it returns 0. Sub‐
79       strings are delimited by commas and the end of the mnt_mntopts string.
80
81   putmntent()
82       The putmntent() function is obsolete and  no  longer  has  any  effect.
83       Entries appear in mnttab as a side effect of a mount(2) call. The func‐
84       tion name is still defined for transition purposes.
85
86   resetmnttab()
87       The resetmnttab() function notifies getextmntent() to reload  from  the
88       kernel  the  device information that corresponds to the new snapshot of
89       the mnttab information (see mnttab(4)). Subsequent getextmntent() calls
90       then  return  correct  extmnttab  information.  This function should be
91       called whenever the  mnttab  file  is  either  rewound  or  closed  and
92       reopened before any calls are made to getextmntent().
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RETURN VALUES

95   getmntent() and getmntany()
96       If  the  next  entry  is successfully read by getmntent() or a match is
97       found with getmntany(), 0 is returned.  If an  EOF  is  encountered  on
98       reading, these functions return −1. If an error is encountered, a value
99       greater than 0 is returned. The following error values are  defined  in
100       <sys/mnttab.h>:
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102       MNT_TOOLONG    A  line in the file exceeded the internal buffer size of
103                      MNT_LINE_MAX.
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106       MNT_TOOMANY    A line in the file contains too many fields.
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109       MNT_TOOFEW     A line in the file contains too few fields.
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112   hasmntopt()
113       Upon successful completion, hasmntopt() returns the address of the sub‐
114       string if a match is found. Otherwise, it returns 0.
115
116   putmntent()
117       The putmntent() is obsolete and always returns −1.
118

ATTRIBUTES

120       See attributes(5) for descriptions of the following attributes:
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125       ┌─────────────────────────────┬─────────────────────────────┐
126       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
127       ├─────────────────────────────┼─────────────────────────────┤
128       │MT-Level                     │Safe                         │
129       └─────────────────────────────┴─────────────────────────────┘
130

NAME

SYNOPSIS

DESCRIPTION

RETURN VALUES

ATTRIBUTES

SEE ALSO