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