V10/man/man3/getpwent.3

.TH GETPWENT 3
.CT 2 secur
.SH NAME
getpwent, getpwuid, getpwnam, setpwent, endpwent, pwdecode \(mi get password file entry
.SH SYNOPSIS
.nf
.B #include <pwd.h>
.PP
.B struct passwd *getpwent()
.PP
.B struct passwd *getpwuid(uid)
.B int uid;
.PP
.B struct passwd *getpwnam(name)
.B char *name;
.PP
.B int setpwent()
.PP
.B int endpwent()
.PP
.B struct passwd *pwdecode(p)
.B char *p;
.fi
.SH DESCRIPTION
.I Getpwent,
.I getpwuid
and
.I getpwnam
each return a pointer to a structure
containing the broken-out
fields of a line in
.FR /etc/passwd .
.EX
.ta \w'struct 'u +\w'passwd 'u +\w'*pw_comment; 'u
struct	passwd	{
	\fLchar	*pw_name;\fR	login name
	\fLchar	*pw_passwd;\fP	encrypted password
	\fLint	pw_uid;\fP	numeric userid
	\fLint	pw_gid;\fP	numeric groupid
	\fLint	pw_quota;\fP	unused
	\fLchar	*pw_comment;\fP	unused
	\fLchar	*pw_gecos;\fP	field for local use
	\fLchar	*pw_dir;\fP	login directory
	\fLchar	*pw_shell;\fP	program to use as Shell
\fL};\fP
.EE
.PP
.I Getpwent
reads the next
line (opening the file if necessary);
.I setpwent
rewinds the file;
.I endpwent
closes it.
.PP
.I Getpwuid
and
.I getpwnam
search from the beginning until a matching
.I uid
or
.I name
is found
(or until end-of-file is encountered).
.PP
.I Pwdecode
breaks out a null-terminated character string
.I p
containing a password file entry.
The input string is modified by the call and
the output structure contains pointers into it.
.SH FILES
.TP
.F /etc/passwd
.SH "SEE ALSO"
.IR getlogin (3), 
.IR getgrent (3), 
.IR passwd (5)
.SH DIAGNOSTICS
These routines return 0 for end of file or error.
.SH BUGS
The return values point to static data
whose content is overwritten by each call.