usr/src/usr.bin/mkstr/mkstr.1

.\" Copyright (c) 1980, 1990 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" %sccs.include.redist.roff%
.\"
.\"     @(#)mkstr.1     6.6 (Berkeley) %G%
.\"
.Dd
.Dt MKSTR 1
.Os
.Sh NAME
.Nm mkstr
.Nd create an error message file by massaging C source
.Sh SYNOPSIS
.Nm mkstr
.Op Fl
.Ar messagefile
.Ar prefix file ...
.Sh DESCRIPTION
.Nm Mkstr
creates files containing error messages extracted from C source,
and restructures the same C source, to utilize the created error message
file.
The intent of
.Nm mkstr
was to reduce the size of large programs and
reduce swapping (see
.Sx BUGS
section below).
.Pp
.Nm Mkstr
processes each of the specified
.Ar files ,
placing a restructured version of the input in a file whose name
consists of the specified
.Ar prefix
and the original name.
A typical usage of
.Nm mkstr
is
.Bd -literal -offset indent
mkstr pistrings xx *.c
.Ed
.Pp
This command causes all the error messages from the C source
files in the current directory to be placed in the file
.Ar pistrings
and restructured copies of the sources to be placed in
files whose names are prefixed with
.Ar \&xx .
.Pp
Options:
.Bl -tag -width indent
.It Fl
Error messages are placed at the end of the specified
message file for recompiling part of a large
.Nm mkstr
ed
program.
.El
.Pp
.Nm mkstr
finds error messages in the source by
searching for the string
.Li \&`error("'
in the input stream.
Each time it occurs, the C string starting at the
.Sq \&"\&
is stored
in the message file followed by a null character and a new-line character;
The new source is restructured with
.Xr lseek 2
pointers into the error message file for retrieval.
.Bd -literal -offset indent
char efilname = "/usr/lib/pi_strings";
int efil = -1;

error(a1, a2, a3, a4)
\&{
        char buf[256];

        if (efil < 0) {
                efil = open(efilname, 0);
                if (efil < 0) {
oops:
                        perror(efilname);
                        exit 1 ;
                }
        }
        if (lseek(efil, (long) a1, 0) \ read(efil, buf, 256) <= 0)
                goto oops;
        printf(buf, a2, a3, a4);
}
.Ed
.Sh SEE ALSO
.Xr lseek 2 ,
.Xr xstr 1
.Sh HISTORY
.Nm Mkstr
appeared in
.Bx 3.0 .
.Sh BUGS
.Nm mkstr
was intended for the limited architecture of the PDP 11 family.
Very few programs actually use it. The pascal interpreter,
.Xr \&pi 1
and the editor,
.Xr \&ex 1
are two programs that are built this way.
It is not an efficient method, the error messages
should be stored in the program text.