1.\" $NetBSD: zopen.3,v 1.7 2003/08/07 11:13:29 agc 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. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" @(#)zopen.3 8.1 (Berkeley) 6/9/93 31.\" 32.Dd June 9, 1993 33.Dt ZOPEN 3 34.Os 35.Sh NAME 36.Nm zopen 37.Nd compressed stream open function 38.Sh SYNOPSIS 39.In stdio.h 40.Ft FILE * 41.Fn zopen "const char *path" "const char *mode" "int bits" 42.Sh DESCRIPTION 43The 44.Fn zopen 45function 46opens the compressed file whose name is the string pointed to by 47.Fa path 48and associates a stream with it. 49.Pp 50The argument 51.Fa mode 52points to one of the following one-character strings: 53.Bl -tag -width indent 54.It Dq Li r 55Open compressed file for reading. 56The stream is positioned at the beginning of the file. 57.It Dq Li w 58Truncate file to zero length or create compressed file for writing. 59The stream is positioned at the beginning of the file. 60.El 61.Pp 62Any created files will have mode 63.Pf \\*q Dv S_IRUSR 64\&| 65.Dv S_IWUSR 66\&| 67.Dv S_IRGRP 68\&| 69.Dv S_IWGRP 70\&| 71.Dv S_IROTH 72\&| 73.Dv S_IWOTH Ns \\*q 74.Pq Li 0666 , 75as modified by the process' 76umask value (see 77.Xr umask 2 ) . 78.Pp 79Files may only be read or written. 80Seek operations are not allowed. 81.Pp 82The 83.Fa bits 84argument, if non-zero, is set to the bits code limit. 85If zero, the default is 16. 86See 87.Fn compress 1 88for more information. 89.Sh RETURN VALUES 90Upon successful completion 91.Fn zopen 92returns a 93.Tn FILE 94pointer. 95Otherwise, 96.Dv NULL 97is returned and the global variable 98.Va errno 99is set to indicate the error. 100.Sh ERRORS 101.Bl -tag -width [EINVAL] 102.It Bq Er EINVAL 103The 104.Fa mode 105or 106.Fa bits 107arguments specified to 108.Fn zopen 109were invalid. 110.It Bq Er EFTYPE 111The compressed file starts with an invalid header, or the compressed 112file is compressed with more bits than can be handled. 113.El 114.Pp 115The 116.Fn zopen 117function may also fail and set 118.Va errno 119for any of the errors specified for the routines 120.Xr fopen 3 121or 122.Xr funopen 3 . 123.Sh SEE ALSO 124.Xr compress 1 , 125.Xr fopen 3 , 126.Xr funopen 3 127.Sh HISTORY 128The 129.Nm zopen 130function 131first appeared in 132.Bx 4.4 . 133.Sh BUGS 134The 135.Fn zopen 136function 137may not be portable to systems other than 138.Bx . 139