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mkstr will process each specified file, placing a massaged version of the input file in a file whose name consists of the specified prefix and the original name. The optional dash (``-'') causes the error messages to be placed at the end of the specified message file for recompiling part of a large mkstred program.
A typical mkstr command line is:
mkstr pistrings xx *.c
This command causes all the error messages from the C source files in the current directory to be placed in the file pistrings and processed copies of the source for these files to be placed in files whose names are prefixed with xx.
To process the error messages in the source to the message file,
mkstr keys on the string `error("' in the input stream.
Each time it occurs, the C string starting at the `"' is placed
in the message file followed by a null character and a newline
character; the null character terminates the message so it can
be easily used when retrieved, the newline character makes it
possible to sensibly cat the error message file to see its contents.
The massaged copy of the input file then contains a lseek
pointer into the file which can be used to retrieve the message.
For example, the command changes
error(``Error on reading'', a2, a3, a4);
into
error(m, a2, a3, a4);
where m is the seek position of the string in the resulting error message file. The programmer must create a routine error which opens the message file, reads the string, and prints it out.
The following example illustrates such a routine.
char efilname[] = "/usr/lib/pi_strings"; int efil = -1;error(a1, a2, a3, a4) int a1, a2, a3, a4; { char buf[256];
if (efil < 0) { efil = open(efilname, 0); if (efil < 0) { perror(efilname); exit(1); } } if (lseek(efil, (long) a1, 0) || read(efil, buf, 256) <= 0) { printf("Unable to find error msg "); printf("at seek address %d\n",a1); exit(1); } printf(buf, a2, a3, a4); }