CGETCAP(3) | Library Functions Manual | CGETCAP(3) |
cgetent
, cgetset
,
cgetmatch
, cgetcap
,
cgetnum
, cgetstr
,
cgetustr
, cgetfirst
,
cgetnext
, cgetclose
,
csetexpandtc
—
#include <stdlib.h>
int
cgetent
(char
**buf, const char * const
*db_array, const char
*name);
int
cgetset
(const
char *ent);
int
cgetmatch
(const
char *buf, const char
*name);
char *
cgetcap
(char
*buf, const char
*cap, int
type);
int
cgetnum
(char
*buf, const char
*cap, long
*num);
int
cgetstr
(char
*buf, const char
*cap, char
**str);
int
cgetustr
(char
*buf, const char
*cap, char
**str);
int
cgetfirst
(char
**buf, const char * const
*db_array);
int
cgetnext
(char
**buf, const char * const
*db_array);
int
cgetclose
(void);
void
csetexpandtc
(int
expandtc);
cgetent
() extracts the capability
name from the database specified by the
NULL
terminated file array
db_array and returns a pointer to a
malloc(3)'d copy of it in
buf. cgetent
() will first look
for files ending in .db (see
cap_mkdb(1)) before accessing
the ASCII file.
buf must be retained through all subsequent
calls to cgetmatch
(),
cgetcap
(), cgetnum
(),
cgetstr
(), and cgetustr
(),
but may then be free(3)'d.
On success 0 is returned, 1 if the returned record contains an unresolved “tc” expansion, -1 if the requested record couldn't be found, -2 if a system error was encountered (couldn't open/read a file, etc.) also setting errno, and -3 if a potential reference loop is detected (see “tc=name” comments below).
cgetset
() enables the addition of a
character buffer containing a single capability record entry to the
capability database. Conceptually, the entry is added as the first
“file” in the database, and is therefore searched first on the
call to cgetent
(). The entry is passed in
ent. If ent is
NULL
, the current entry is removed from the
database.
cgetset
() must precede the database
traversal. It must be called before the cgetent
()
call. If a sequential access is being performed (see below), it must be
called before the first sequential access call
(cgetfirst
() or cgetnext
()),
or be directly preceded by a cgetclose
() call. On
success 0 is returned and -1 on failure.
cgetmatch
() will return 0 if
name is one of the names of the capability record
buf, -1 if not.
cgetcap
() searches the capability record
buf for the capability cap with
type type. A type is specified
using any single character. If a colon (‘:’) is used, an
untyped capability will be searched for (see below for explanation of
types). A pointer to the value of cap in
buf is returned on success,
NULL
if the requested capability couldn't be found.
The end of the capability value is signaled by a ‘:’. See
capfile(5) for a description
of the capability syntax.
cgetnum
() retrieves the value of the
numeric capability cap from the capability record
pointed to by buf. The numeric value is returned in
the long pointed to by num. 0 is
returned on success, -1 if the requested numeric capability couldn't be
found.
cgetstr
() retrieves the value of the
string capability cap from the capability record
pointed to by buf. A pointer to a decoded,
NUL
terminated,
malloc(3)'d copy of the string
is returned in the char * pointed to by
str. The number of characters in the decoded string
not including the trailing NUL
is returned on
success, -1 if the requested string capability couldn't be found, -2 if a
system error was encountered (storage allocation failure).
cgetustr
() is identical to
cgetstr
() except that it does not expand special
characters, but rather returns each character of the capability string
literally.
cgetfirst
(),
cgetnext
(), comprise a function group that provides
for sequential access of the NULL
pointer terminated
array of file names, db_array.
cgetfirst
() returns the first record in the database
and resets the access to the first record.
cgetnext
() returns the next record in the database
with respect to the record returned by the previous
cgetfirst
() or cgetnext
()
call. If there is no such previous call, the first record in the database is
returned. Each record is returned in a
malloc(3)'d copy pointed to by
buf. “tc” expansion is done (see
“tc=name” comments below).
Upon completion of the database 0 is returned, 1 is returned upon successful return of record with possibly more remaining (we haven't reached the end of the database yet), 2 is returned if the record contains an unresolved “tc” expansion, -1 is returned if an system error occurred, and -2 is returned if a potential reference loop is detected (see “tc=name” comments below). Upon completion of database (0 return) the database is closed.
cgetclose
() closes the sequential access
and frees any memory and file descriptors being used. Note that it does not
erase the buffer pushed by a call to cgetset
().
cgetcap
() will
return a pointer to a value of a name given the capability name and the type
of the value.
The types ‘#’ and ‘=’ are
conventionally used to denote numeric and string typed values, but no
restriction on those types is enforced. The functions
cgetnum
() and cgetstr
() can
be used to implement the traditional syntax and semantics of
‘#’ and ‘=’. Typeless capabilities are typically
used to denote boolean objects with presence or absence indicating truth and
false values respectively. This interpretation is conveniently represented
by:
(getcap(buf, name, ':') !=
NULL)
A special capability, “tc=name”, is used to indicate that the record specified by name should be substituted for the “tc” capability. “tc” capabilities may interpolate records which also contain “tc” capabilities and more than one “tc” capability may be used in a record. A “tc” expansion scope (i.e. where the argument is searched for) contains the file in which the “tc” is declared and all subsequent files in the file array.
csetexpandtc
() can be used to control if
“tc” expansion is performed or not.
cgetent
(), cgetset
(),
cgetmatch
(), cgetnum
(),
cgetstr
(), cgetustr
(),
cgetfirst
(), and cgetnext
()
return a value greater than or equal to 0 on success and a value less than 0
on failure. cgetcap
() returns a character pointer on
success and a NULL
on failure.
cgetclose
(),
cgetent
(), cgetfirst
(), and
cgetnext
() may fail and set
errno for any of the errors specified for the library
functions: fopen(3),
fclose(3),
open(2), and
close(2).
cgetent
(),
cgetset
(), cgetstr
(), and
cgetustr
() may fail and set
errno as follows:
ENOMEM
]cgetent
().
The buffer added to the database by a call to
cgetset
() is not unique to the database but is
rather prepended to any database used.
April 5, 2012 | NetBSD 9.0 |