1.\" $NetBSD: zopen.3,v 1.5 2002/02/08 01:36:21 ross Exp $ 2.\" 3.\" Copyright (c) 1992, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)zopen.3 8.1 (Berkeley) 6/9/93 35.\" 36.Dd June 9, 1993 37.Dt ZOPEN 3 38.Os 39.Sh NAME 40.Nm zopen 41.Nd compressed stream open function 42.Sh SYNOPSIS 43.Fd #include \*[Lt]stdio.h\*[Gt] 44.Ft FILE * 45.Fn zopen "const char *path" "const char *mode" "int bits" 46.Sh DESCRIPTION 47The 48.Fn zopen 49function 50opens the compressed file whose name is the string pointed to by 51.Fa path 52and associates a stream with it. 53.Pp 54The argument 55.Fa mode 56points to one of the following one-character strings: 57.Bl -tag -width indent 58.It Dq Li r 59Open compressed file for reading. 60The stream is positioned at the beginning of the file. 61.It Dq Li w 62Truncate file to zero length or create compressed file for writing. 63The stream is positioned at the beginning of the file. 64.El 65.Pp 66Any created files will have mode 67.Pf \\*q Dv S_IRUSR 68\&| 69.Dv S_IWUSR 70\&| 71.Dv S_IRGRP 72\&| 73.Dv S_IWGRP 74\&| 75.Dv S_IROTH 76\&| 77.Dv S_IWOTH Ns \\*q 78.Pq Li 0666 , 79as modified by the process' 80umask value (see 81.Xr umask 2 ) . 82.Pp 83Files may only be read or written. 84Seek operations are not allowed. 85.Pp 86The 87.Fa bits 88argument, if non-zero, is set to the bits code limit. 89If zero, the default is 16. 90See 91.Fn compress 1 92for more information. 93.Sh RETURN VALUES 94Upon successful completion 95.Fn zopen 96returns a 97.Tn FILE 98pointer. 99Otherwise, 100.Dv NULL 101is returned and the global variable 102.Va errno 103is set to indicate the error. 104.Sh ERRORS 105.Bl -tag -width [EINVAL] 106.It Bq Er EINVAL 107The 108.Fa mode 109or 110.Fa bits 111arguments specified to 112.Fn zopen 113were invalid. 114.It Bq Er EFTYPE 115The compressed file starts with an invalid header, or the compressed 116file is compressed with more bits than can be handled. 117.El 118.Pp 119The 120.Fn zopen 121function may also fail and set 122.Va errno 123for any of the errors specified for the routines 124.Xr fopen 3 125or 126.Xr funopen 3 . 127.Sh SEE ALSO 128.Xr compress 1 , 129.Xr fopen 3 , 130.Xr funopen 3 131.Sh HISTORY 132The 133.Nm zopen 134function 135first appeared in 136.Bx 4.4 . 137.Sh BUGS 138The 139.Fn zopen 140function 141may not be portable to systems other than 142.Bx . 143