GETPW(3) Linux Programmer's Manual GETPW(3)

getpw - reconstruct password line entry

#define _GNU_SOURCE             /* See feature_test_macros(7) */
#include <sys/types.h>
#include <pwd.h>
int getpw(uid_t uid, char *buf);

The getpw() function reconstructs the password line entry for the given user ID uid in the buffer buf. The returned buffer contains a line of format

name:passwd:uid:gid:gecos:dir:shell

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 getpw() function returns 0 on success; on error, it returns -1, and errno is set to indicate the error.
If uid is not found in the password database, getpw() returns -1, sets errno to 0, and leaves buf unchanged.

0 or ENOENT
No user corresponding to uid.
EINVAL
buf is NULL.
ENOMEM
Insufficient memory to allocate passwd structure.

/etc/passwd
password database file

For an explanation of the terms used in this section, see attributes(7).
Interface Attribute Value
getpw () Thread safety MT-Safe locale

SVr2.

The getpw() function is dangerous as it may overflow the provided buffer buf. It is obsoleted by getpwuid(3).

endpwent(3), fgetpwent(3), getpwent(3), getpwnam(3), getpwuid(3), putpwent(3), setpwent(3), passwd(5)
2017-09-15 GNU