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. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. 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.\" @(#)xstr.1 8.2 (Berkeley) 12/30/93 33.\" $FreeBSD: src/usr.bin/xstr/xstr.1,v 1.4.2.4 2002/06/21 15:30:26 charnier Exp $ 34.\" $DragonFly: src/usr.bin/xstr/xstr.1,v 1.3 2006/02/17 19:39:18 swildner Exp $ 35.\" 36.Dd December 30, 1993 37.Dt XSTR 1 38.Os 39.Sh NAME 40.Nm xstr 41.Nd "extract strings from C programs to implement shared strings" 42.Sh SYNOPSIS 43.Nm 44.Op Fl c 45.Op Fl 46.Op Fl v 47.Op Ar file 48.Sh DESCRIPTION 49The 50.Nm 51utility maintains a file 52.Pa strings 53into which strings in component parts of a large program are hashed. 54These strings are replaced with references to this common area. 55This serves to implement shared constant strings, most useful if they 56are also read-only. 57.Pp 58Available options: 59.Bl -tag -width Ds 60.It Fl 61Read from the standard input. 62.It Fl c 63Extract the strings from the C source 64.Ar file 65or the standard input 66.Pq Fl , 67replacing 68string references by expressions of the form (&xstr[number]) 69for some number. 70An appropriate declaration of 71.Nm 72is prepended to the file. 73The resulting C text is placed in the file 74.Pa x.c , 75to then be compiled. 76The strings from this file are placed in the 77.Pa strings 78data base if they are not there already. 79Repeated strings and strings which are suffixes of existing strings 80do not cause changes to the data base. 81.It Fl v 82Verbose mode. 83.El 84.Pp 85After all components of a large program have been compiled a file 86.Pa xs.c 87declaring the common 88.Nm 89space can be created by a command of the form 90.Bd -literal -offset indent 91xstr 92.Ed 93.Pp 94The file 95.Pa xs.c 96should then be compiled and loaded with the rest 97of the program. 98If possible, the array can be made read-only (shared) saving 99space and swap overhead. 100.Pp 101The 102.Nm 103utility can also be used on a single file. 104A command 105.Bd -literal -offset indent 106xstr name 107.Ed 108.Pp 109creates files 110.Pa x.c 111and 112.Pa xs.c 113as before, without using or affecting any 114.Pa strings 115file in the same directory. 116.Pp 117It may be useful to run 118.Nm 119after the C preprocessor if any macro definitions yield strings 120or if there is conditional code which contains strings 121which may not, in fact, be needed. 122An appropriate command sequence for running 123.Nm 124after the C preprocessor is: 125.Pp 126.Bd -literal -offset indent -compact 127cc \-E name.c | xstr \-c \- 128cc \-c x.c 129mv x.o name.o 130.Ed 131.Pp 132The 133.Nm 134utility does not touch the file 135.Pa strings 136unless new items are added, thus 137.Xr make 1 138can avoid remaking 139.Pa xs.o 140unless truly necessary. 141.Sh FILES 142.Bl -tag -width /tmp/xsxx* -compact 143.It Pa strings 144Data base of strings 145.It Pa x.c 146Massaged C source 147.It Pa xs.c 148C source for definition of array `xstr' 149.It Pa /tmp/xs* 150Temp file when `xstr name' doesn't touch 151.Pa strings 152.El 153.Sh SEE ALSO 154.Xr mkstr 1 155.Sh HISTORY 156The 157.Nm 158command appeared in 159.Bx 3.0 . 160.Sh BUGS 161If a string is a suffix of another string in the data base, 162but the shorter string is seen first by 163.Nm 164both strings will be placed in the data base, when just 165placing the longer one there will do. 166