1.\" Copyright (c) 1980, 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.Dd December 30, 1993 29.Dt XSTR 1 30.Os 31.Sh NAME 32.Nm xstr 33.Nd "extract strings from C programs to implement shared strings" 34.Sh SYNOPSIS 35.Nm 36.Op Fl cv 37.Op Fl 38.Op Ar 39.Sh DESCRIPTION 40The 41.Nm 42utility maintains a file 43.Pa strings 44into which strings in component parts of a large program are hashed. 45These strings are replaced with references to this common area. 46This serves to implement shared constant strings, most useful if they 47are also read-only. 48.Pp 49The following options are available: 50.Bl -tag -width indent 51.It Fl 52Read from the standard input. 53.It Fl c 54Extract the strings from the C source 55.Ar file 56or the standard input 57.Pq Fl , 58replacing 59string references by expressions of the form 60.Li (&xstr[number]) 61for some 62.Ar number . 63An appropriate declaration of 64.Va xstr 65is prepended to the file. 66The resulting C text is placed in the file 67.Pa x.c , 68to then be compiled. 69The strings from this file are placed in the 70.Pa strings 71data base if they are not there already. 72Repeated strings and strings which are suffixes of existing strings 73do not cause changes to the data base. 74.It Fl v 75Verbose mode. 76.El 77.Pp 78After all components of a large program have been compiled a file 79.Pa xs.c 80declaring the common 81.Va xstr 82space can be created by a command of the form 83.Pp 84.Dl xstr 85.Pp 86The file 87.Pa xs.c 88should then be compiled and loaded with the rest 89of the program. 90If possible, the array can be made read-only (shared) saving 91space and swap overhead. 92.Pp 93The 94.Nm 95utility can also be used on a single file. 96A command 97.Bd -literal -offset indent 98xstr name 99.Ed 100.Pp 101creates files 102.Pa x.c 103and 104.Pa xs.c 105as before, without using or affecting any 106.Pa strings 107file in the same directory. 108.Pp 109It may be useful to run 110.Nm 111after the C preprocessor if any macro definitions yield strings 112or if there is conditional code which contains strings 113which may not, in fact, be needed. 114An appropriate command sequence for running 115.Nm 116after the C preprocessor is: 117.Pp 118.Bd -literal -offset indent -compact 119cc -E name.c | xstr -c - 120cc -c x.c 121mv x.o name.o 122.Ed 123.Pp 124The 125.Nm 126utility does not touch the file 127.Pa strings 128unless new items are added, thus 129.Xr make 1 130can avoid remaking 131.Pa xs.o 132unless truly necessary. 133.Sh FILES 134.Bl -tag -width ".Pa /tmp/xs*" -compact 135.It Pa strings 136data base of strings 137.It Pa x.c 138massaged C source 139.It Pa xs.c 140C source for definition of array 141.Va xstr 142.It Pa /tmp/xs* 143temporary file when 144.Dq Li "xstr name" 145does not touch 146.Pa strings 147.El 148.Sh SEE ALSO 149.Xr mkstr 1 150.Sh HISTORY 151The 152.Nm 153command appeared in 154.Bx 3.0 . 155.Sh BUGS 156If a string is a suffix of another string in the data base, 157but the shorter string is seen first by 158.Nm 159both strings will be placed in the data base, when just 160placing the longer one there will do. 161