.\" Copyright (c) 1980, 1993
.\" The Regents of the University of California. All rights reserved.
.\" %sccs.include.redist.roff%
.\" @(#)xstr.1 8.2 (Berkeley) %G%
.Nd "extract strings from C programs to implement shared strings"
into which strings in component parts of a large program are hashed.
These strings are replaced with references to this common area.
This serves to implement shared constant strings, most useful if they
reads from the standard input.
will extract the strings from the C source
string references by expressions of the form (&xstr[number])
An appropriate declaration of
is prepended to the file.
The resulting C text is placed in the file
The strings from this file are placed in the
data base if they are not there already.
Repeated strings and strings which are suffixes of existing strings
do not cause changes to the data base.
After all components of a large program have been compiled a file
space can be created by a command of the form
.Bd -literal -offset indent
should then be compiled and loaded with the rest
If possible, the array can be made read-only (shared) saving
can also be used on a single file.
.Bd -literal -offset indent
as before, without using or affecting any
file in the same directory.
after the C preprocessor if any macro definitions yield strings
or if there is conditional code which contains strings
which may not, in fact, be needed.
An appropriate command sequence for running
after the C preprocessor is:
.Bd -literal -offset indent -compact
cc \-E name.c | xstr \-c \-
unless new items are added, thus
.Bl -tag -width /tmp/xsxx* -compact
C source for definition of array `xstr'
Temp file when `xstr name' doesn't touch
If a string is a suffix of another string in the data base,
but the shorter string is seen first by
both strings will be placed in the data base, when just
placing the longer one there will do.