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/* ------------------------------------------------------------------ */
/* Decimal Number Library Demonstration program */
/* ------------------------------------------------------------------ */
/* Copyright (c) IBM Corporation, 2001. All rights reserved. */
/* ----------------------------------------------------------------+- */
/* right margin -->| */
// example4.c -- add two numbers, active error handling
// Arguments are two numbers
#define DECNUMDIGITS 38 // work with up to 38 digits
#include "decNumber.h" // base number library
#include <stdio.h> // for printf
// [snip...
#include <signal.h> // signal handling
#include <setjmp.h> // setjmp/longjmp
jmp_buf preserve; // stack snapshot
void signalHandler(int); // prototype for GCC
void signalHandler(int sig) {
signal(SIGFPE, signalHandler); // re-enable
longjmp(preserve, sig); // branch to preserved point
}
// ...snip]
int main(int argc, char *argv[]) {
decNumber a, b; // working numbers
decContext set; // working context
char string[DECNUMDIGITS+14]; // conversion buffer
int value; // work variable
if (argc<3) { // not enough words
printf("Please supply two numbers to add.\n");
return 1;
}
decContextDefault(&set, DEC_INIT_BASE); // initialize
// [snip...
signal(SIGFPE, signalHandler); // set up signal handler
value=setjmp(preserve); // preserve and test environment
if (value) { // (non-0 after longjmp)
set.status &= DEC_Errors; // keep only errors
printf("Signal trapped [%s].\n", decContextStatusToString(&set));
return 1;
}
// ...snip]
// [change from Example 1, here]
// leave traps enabled
set.digits=DECNUMDIGITS; // set precision
decNumberFromString(&a, argv[1], &set);
decNumberFromString(&b, argv[2], &set);
decNumberAdd(&a, &a, &b, &set); // A=A+B
decNumberToString(&a, string);
printf("%s + %s => %s\n", argv[1], argv[2], string);
return 0;
} // main
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