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