dear maintainer: the fallowing is a small sample of the code that contains all the info to reproduce the problem. the C library function isdigit() fails and causes segmention fault when the input is is not numeric like xx.
COMPILE COMMAND : >> gcc -ansi --version -Wall -o ch2-13.out -lm ch2-13.c
/* USER NAME : vartan * DATE STARTED : Wed Jul 01 19:28:34 2009 * * COMPILE COMMAND : gcc -ansi --version -Wall -o ch2-13.out -lm ch2-13.c */ /* INCLUDE FILES */ #include <stdio.h> #include <math.h> #include <stdlib.h> #include <ctype.h> /* PREPROCESSOR CONSTANTS */ int main(void){ /* start of main */ int i = 1, devisor, j = 0; do { printf("Please enter a valid numeric for devisor\n"); scanf("%d", &devisor); } while (isdigit(devisor)); printf ("counting\n"); while (i <= 100) { if (!( i++ % devisor)) { printf("%4d",(i-1)); /* point to the correct line number that is devidable by devisor*/ printf(" *\n"); j++; } else ; } /* end of while */ printf("\n The number of lines that is dividable by %d was %d.\n", devisor,j); return(0); } /* end of main */