xref: /openbsd-src/lib/libutil/pw_init.3 (revision db3296cf5c1dd9058ceecc3a29fe4aaa0bd26000)
1.\"	$OpenBSD: pw_init.3,v 1.7 2003/06/02 20:18:42 millert Exp $
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8.\" BG 91-66 and contributed to Berkeley.
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34.Dd December 15, 1995
35.Dt PW_INIT 3
36.Os
37.Sh NAME
38.Nm pw_init ,
39.Nm pw_setdir ,
40.Nm pw_file ,
41.Nm pw_edit ,
42.Nm pw_prompt ,
43.Nm pw_copy ,
44.Nm pw_scan ,
45.Nm pw_error
46.Nd utility functions for interactive passwd file updates
47.Sh SYNOPSIS
48.Fd #include <pwd.h>
49.Fd #include <util.h>
50.Ft void
51.Fn pw_init
52.Ft void
53.Fn pw_setdir "const char *directory"
54.Ft char *
55.Fn pw_file "const char *filename"
56.Ft void
57.Fn pw_edit "int notsetuid" "const char *filename"
58.Ft void
59.Fn pw_prompt
60.Ft void
61.Fn pw_copy "int ffd" "int tfd" "struct passwd *pw"
62.Ft int
63.Fn pw_scan "char *bp" "struct passwd *pw" "int *flags"
64.Ft void
65.Fn pw_error "const char *name" "int err" "int eval"
66.Sh DESCRIPTION
67These functions are designed as conveniences for interactive programs
68which update the passwd file and do nothing else.
69They generally
70handle errors by printing out a message to the standard error stream
71and possibly aborting the process.
72.Pp
73The
74.Fn pw_init
75function prepares for a passwd update by unlimiting all resource
76constraints, disabling core dumps (thus preventing dumping the
77contents of the passwd database into a world-readable file), and
78disabling most signals.
79.Pp
80The
81.Fn pw_setdir
82function sets an alternative directory where the rest of the functions look
83for password-related files.
84Use this if you are writing utilities that should
85be able to handle password files outside of
86.Pa /etc .
87.Pp
88The
89.Fn pw_file
90function transforms filenames so that they end up in the directory specified
91to the latest
92.Fn pw_setdir
93call.
94The rule is that all directories are stripped of the given name and
95only the filename is appended to the directory.
96.Pp
97The
98.Fn pw_edit
99function runs an editor (named by the environment variable EDITOR, or
100.Pa /usr/bin/vi
101if EDITOR is not set) on the file
102.Fa filename
103(or
104.Pa /etc/ptmp
105if
106.Fa filename
107is NULL).
108If
109.Fa notsetuid
110is nonzero,
111.Fn pw_edit
112will set the effective user and group ID to the real user and group ID
113before running the editor.
114.Pp
115The
116.Fn pw_prompt
117function asks the user whether he or she wants to re-edit the password
118file; if the answer is no,
119.Fn pw_prompt
120deletes the lock file and exits the process.
121.Pp
122The
123.Fn pw_copy
124function reads a passwd file from
125.Fa ffd
126and writes it to
127.Fa tfd ,
128updating the entry corresponding to pw->pw_name with the information
129in
130.Fa pw .
131.Pp
132The
133.Fn pw_scan
134function accepts in
135.Fa bp
136a passwd entry as it would be represented in
137.Pa /etc/master.passwd
138and fills in
139.Fa pw
140with corresponding values; string fields in
141.Fa pw
142will be pointers into
143.Fa bp .
144Some characters in
145.Fa bp
146will be overwritten with 0s in order to terminate the strings pointed
147to by
148.Fa pw .
149If
150.Fa flags
151is non-null, it is filled in with the following flags:
152.Bl -tag -width _PASSWORD_NOGIDxxx
153.It Dv _PASSWORD_NOUID
154The uid field of
155.Fa bp
156is empty.
157.It Dv _PASSWORD_NOGID
158The gid field of
159.Fa bp
160is empty.
161.It Dv _PASSWD_NOCHG
162The change field of
163.Fa bp
164is empty.
165.It Dv _PASSWD_NOEXP
166The expire field of
167.Fa bp
168is empty.
169.El
170.Pp
171The
172.Fn pw_error
173function displays an error message, aborts the current passwd update,
174and exits the current process.
175If
176.Fa err
177is non-zero, a warning message beginning with
178.Fa name
179is printed for the current value of
180.Va errno .
181The process exits with status
182.Fa eval .
183.Sh RETURN VALUES
184The
185.Fn pw_scan
186function prints a warning message and returns 0 if the string in the
187.Fa bp
188argument is not a valid passwd string.
189Otherwise,
190.Fn pw_scan
191returns 1.
192.Sh FILES
193.Bl -tag -width /etc/master.passwd -compact
194.It Pa /etc/master.passwd
195.It Pa /etc/ptmp
196.El
197.Sh SEE ALSO
198.Xr pw_lock 3 ,
199.Xr passwd 5
200