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Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" From: @(#)getpwent.3 8.2 (Berkeley) 12/11/93 33.\" $FreeBSD$ 34.\" 35.Dd April 16, 2003 36.Dt GETPWENT 3 37.Os 38.Sh NAME 39.Nm getpwent , 40.Nm getpwent_r , 41.Nm getpwnam , 42.Nm getpwnam_r , 43.Nm getpwuid , 44.Nm getpwuid_r , 45.Nm setpassent , 46.Nm setpwent , 47.Nm endpwent 48.Nd password database operations 49.Sh LIBRARY 50.Lb libc 51.Sh SYNOPSIS 52.In sys/types.h 53.In pwd.h 54.Ft struct passwd * 55.Fn getpwent void 56.Ft int 57.Fn getpwent_r "struct passwd *pwd" "char *buffer" "size_t bufsize" "struct passwd **result" 58.Ft struct passwd * 59.Fn getpwnam "const char *login" 60.Ft int 61.Fn getpwnam_r "const char *name" "struct passwd *pwd" "char *buffer" "size_t bufsize" "struct passwd **result" 62.Ft struct passwd * 63.Fn getpwuid "uid_t uid" 64.Ft int 65.Fn getpwuid_r "uid_t uid" "struct passwd *pwd" "char *buffer" "size_t bufsize" "struct passwd **result" 66.Ft int 67.Fn setpassent "int stayopen" 68.Ft void 69.Fn setpwent void 70.Ft void 71.Fn endpwent void 72.Sh DESCRIPTION 73These functions 74operate on the password database file 75which is described 76in 77.Xr passwd 5 . 78Each entry in the database is defined by the structure 79.Vt passwd 80found in the include 81file 82.In pwd.h : 83.Bd -literal -offset indent 84struct passwd { 85 char *pw_name; /* user name */ 86 char *pw_passwd; /* encrypted password */ 87 uid_t pw_uid; /* user uid */ 88 gid_t pw_gid; /* user gid */ 89 time_t pw_change; /* password change time */ 90 char *pw_class; /* user access class */ 91 char *pw_gecos; /* Honeywell login info */ 92 char *pw_dir; /* home directory */ 93 char *pw_shell; /* default shell */ 94 time_t pw_expire; /* account expiration */ 95 int pw_fields; /* internal: fields filled in */ 96}; 97.Ed 98.Pp 99The functions 100.Fn getpwnam 101and 102.Fn getpwuid 103search the password database for the given login name or user uid, 104respectively, always returning the first one encountered. 105.Pp 106The 107.Fn getpwent 108function 109sequentially reads the password database and is intended for programs 110that wish to process the complete list of users. 111.Pp 112The functions 113.Fn getpwent_r , 114.Fn getpwnam_r , 115and 116.Fn getpwuid_r 117are thread-safe versions of 118.Fn getpwent , 119.Fn getpwnam , 120and 121.Fn getpwuid , 122respectively. 123The caller must provide storage for the results of the search in 124the 125.Fa pwd , 126.Fa buffer , 127.Fa bufsize , 128and 129.Fa result 130arguments. 131When these functions are successful, the 132.Fa pwd 133argument will be filled-in, and a pointer to that argument will be 134stored in 135.Fa result . 136If an entry is not found or an error occurs, 137.Fa result 138will be set to 139.Dv NULL . 140.Pp 141The 142.Fn setpassent 143function 144accomplishes two purposes. 145First, it causes 146.Fn getpwent 147to ``rewind'' to the beginning of the database. 148Additionally, if 149.Fa stayopen 150is non-zero, file descriptors are left open, significantly speeding 151up subsequent accesses for all of the routines. 152(This latter functionality is unnecessary for 153.Fn getpwent 154as it does not close its file descriptors by default.) 155.Pp 156It is dangerous for long-running programs to keep the file descriptors 157open as the database will become out of date if it is updated while the 158program is running. 159.Pp 160The 161.Fn setpwent 162function 163is identical to 164.Fn setpassent 165with an argument of zero. 166.Pp 167The 168.Fn endpwent 169function 170closes any open files. 171.Pp 172These routines have been written to ``shadow'' the password file, e.g.\& 173allow only certain programs to have access to the encrypted password. 174If the process which calls them has an effective uid of 0, the encrypted 175password will be returned, otherwise, the password field of the returned 176structure will point to the string 177.Ql * . 178.Sh RETURN VALUES 179The functions 180.Fn getpwent , 181.Fn getpwnam , 182and 183.Fn getpwuid 184return a valid pointer to a passwd structure on success 185or 186.Dv NULL 187if the entry is not found or if an error occurs. 188If an error does occur, 189.Va errno 190will be set. 191Note that programs must explicitly set 192.Va errno 193to zero before calling any of these functions if they need to 194distinguish between a non-existent entry and an error. 195The functions 196.Fn getpwent_r , 197.Fn getpwnam_r , 198and 199.Fn getpwuid_r 200return 0 if no error occurred, or an error number to indicate failure. 201It is not an error if a matching entry is not found. 202(Thus, if 203.Fa result 204is 205.Dv NULL 206and the return value is 0, no matching entry exists.) 207.Pp 208The 209.Fn setpassent 210function returns 0 on failure and 1 on success. 211The 212.Fn endpwent 213and 214.Fn setpwent 215functions 216have no return value. 217.Sh FILES 218.Bl -tag -width /etc/master.passwd -compact 219.It Pa /etc/pwd.db 220The insecure password database file 221.It Pa /etc/spwd.db 222The secure password database file 223.It Pa /etc/master.passwd 224The current password file 225.It Pa /etc/passwd 226A Version 7 format password file 227.El 228.Sh COMPATIBILITY 229The historic function 230.Xr setpwfile 3 , 231which allowed the specification of alternate password databases, 232has been deprecated and is no longer available. 233.Sh ERRORS 234These routines may fail for any of the errors specified in 235.Xr open 2 , 236.Xr dbopen 3 , 237.Xr socket 2 , 238and 239.Xr connect 2 , 240in addition to the following: 241.Bl -tag -width Er 242.It Bq Er ERANGE 243The buffer specified by the 244.Fa buffer 245and 246.Fa bufsize 247arguments was insufficiently sized to store the result. 248The caller should retry with a larger buffer. 249.El 250.Sh SEE ALSO 251.Xr getlogin 2 , 252.Xr getgrent 3 , 253.Xr nsswitch.conf 5 , 254.Xr passwd 5 , 255.Xr pwd_mkdb 8 , 256.Xr vipw 8 , 257.Xr yp 8 258.Sh STANDARDS 259The 260.Fn getpwent , 261.Fn getpwnam , 262.Fn getpwnam_r , 263.Fn getpwuid , 264.Fn getpwuid_r , 265.Fn setpwent , 266and 267.Fn endpwent 268functions conform to 269.St -p1003.1-96 . 270.Sh HISTORY 271The 272.Fn getpwent , 273.Fn getpwnam , 274.Fn getpwuid , 275.Fn setpwent , 276and 277.Fn endpwent 278functions appeared in 279.At v7 . 280The 281.Fn setpassent 282function appeared in 283.Bx 4.3 Reno . 284The 285.Fn getpwent_r , 286.Fn getpwnam_r , 287and 288.Fn getpwuid_r 289functions appeared in 290.Fx 5.1 . 291.Sh BUGS 292The functions 293.Fn getpwent , 294.Fn getpwnam , 295and 296.Fn getpwuid , 297leave their results in an internal static object and return 298a pointer to that object. 299Subsequent calls to 300the same function 301will modify the same object. 302.Pp 303The functions 304.Fn getpwent , 305.Fn getpwent_r , 306.Fn endpwent , 307.Fn setpassent , 308and 309.Fn setpwent 310are fairly useless in a networked environment and should be 311avoided, if possible. 312The 313.Fn getpwent 314and 315.Fn getpwent_r 316functions 317make no attempt to suppress duplicate information if multiple 318sources are specified in 319.Xr nsswitch.conf 5 . 320