| 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 10.0 |