qgetpwent_r.3

NAME

qgetpwent_r - get passwd file entry reentrantly

SYNOPSIS

#include <qgetpwgr.h>

int qgetpwent_r(struct passwd *pwbuf, char *buf,
 size_t buflen, struct passwd **pwbufp);

DESCRIPTION

The function qgetpwent_r() is the reentrant versions of qgetpwent(3). It reads the next passwd entry from the stream initialized by setpwent(3).

The passwd structure is defined in <pwd.h> as follows:

struct passwd {
    char    *pw_name;      /* username */
    char    *pw_passwd;    /* user password */
    uid_t    pw_uid;       /* user ID */
    gid_t    pw_gid;       /* group ID */
    char    *pw_gecos;     /* user information */
    char    *pw_dir;       /* home directory */
    char    *pw_shell;     /* shell program */
};

For more information about the fields of this structure, see passwd(5).

The nonreentrant function return a pointer to static storage, where this static storage contains further pointers to user name, password, gecos field, home directory and shell. The reentrant function described here return all of that in caller-provided buffers. First of all there is the buffer pwbuf that can hold a struct passwd. And next the buffer buf of size buflen that can hold additional strings. The result of these functions, the struct passwd read from the stream, is stored in the provided buffer *pwbuf, and a pointer to this struct passwd is returned in *pwbufp.

RETURN VALUE

On success, this function return 0 and *pwbufp is a pointer to the struct passwd. On error, these functions return an error value and *pwbufp is NULL.

ERRORS

ENOENT
No more entries.

ERANGE
Insufficient buffer space supplied. Try again with larger buffer.

ETXTBUSY
Temporary error happened.

NOTES

The function qgetpwent_r() is not really reentrant since it shares the reading position in the stream with all other threads.

SEE ALSO

qgetpwent(3), qgetpwnam(3), qgetpwuid(3), passwd(5)