XSTR
Section: User Commands (1)
Index
Return to Main Contents
BSD mandoc
BSD 3
NAME
xstr
- extract strings from C programs to implement shared strings
SYNOPSIS
xstr
[-c
]
[-
]
[file
]
DESCRIPTION
Xstr
maintains a file
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
are also read-only.
Available options:
- -
-
Xstr
reads from the standard input.
- -c
-
Xstr
will extract the strings from the C source
file
or the standard input
(-
)
replacing
string references by expressions of the form (&xstr[number])
for some number.
An appropriate declaration of
xstr
is prepended to the file.
The resulting C text is placed in the file
x.c
to then be compiled.
The strings from this file are placed in the
strings
data base if they are not there already.
Repeated strings and strings which are suffices of existing strings
do not cause changes to the data base.
After all components of a large program have been compiled a file
xs.c
declaring the common
xstr
space can be created by a command of the form
xstr
The file
xs.c
should then be compiled and loaded with the rest
of the program.
If possible, the array can be made read-only (shared) saving
space and swap overhead.
Xstr
can also be used on a single file.
A command
xstr name
creates files
x.c
and
xs.c
as before, without using or affecting any
strings
file in the same directory.
It may be useful to run
xstr
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
xstr
after the C preprocessor is:
cc -E name.c | xstr -c -
cc -c x.c
mv x.o name.o
Xstr
does not touch the file
strings
unless new items are added, thus
make(1)
can avoid remaking
xs.o
unless truly necessary.
FILES
- strings
-
Data base of strings
- x.c
-
Massaged C source
- xs.c
-
C source for definition of array `xstr'
- /tmp/xs*
-
Temp file when `xstr name' doesn't touch
strings
SEE ALSO
mkstr(1)
BUGS
If a string is a suffix of another string in the data base,
but the shorter string is seen first by
xstr
both strings will be placed in the data base, when just
placing the longer one there will do.
HISTORY
The
xstr
command appeared in
BSD 3.0
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- FILES
-
- SEE ALSO
-
- BUGS
-
- HISTORY
-
This document was created by
man2html,
using the manual pages.
Time: 06:34:06 GMT, May 19, 2025