#include <sys/types.h> #include <pwd.h> struct passwd *getpwent(void); void setpwent(void); void endpwent(void);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
getpwent(), setpwent(), endpwent():
_XOPEN_SOURCE >= 500 || /* glibc >= 2.19: */ _DEFAULT_SOURCE || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
The setpwent() function rewinds to the beginning of the password database.
The endpwent() function is used to close the password database after all processing has been performed.
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 */
};
When shadow(5) passwords are enabled (which is default on many GNU/Linux installations) the content of pw_passwd is usually not very useful. In such a case most passwords are stored in a separate file.
The variable pw_shell may be empty, in which case the system will execute the default shell (/bin/sh) for the user.
For more information about the fields of this structure, see passwd(5).
The return value may point to a static area, and may be overwritten by subsequent calls to getpwent(), getpwnam(3), or getpwuid(3). (Do not pass the returned pointer to free(3).)
Interface | Attribute | Value |
getpwent() | Thread safety |
MT-Unsafe race:pwent
race:pwentbuf locale
|
setpwent(), endpwent() | Thread safety |
MT-Unsafe race:pwent locale
|
In the above table, pwent in race:pwent signifies that if any of the functions setpwent(), getpwent(), or endpwent() are used in parallel in different threads of a program, then data races could occur.