ascii.c

#include <stdio.h>
#include <getopt.h>
#include <string.h>

void dec(char* string);
void hex(char* string);
void oct(char* string);
char* usage(void);

int main(int argc, char* argv[]){

	int index, flags[3] = {0};
	void (*fun_ptr[3])(char*) = {&dec, &hex, &oct};
	char opt;
	while((opt = getopt(argc, argv, ":hdo")) != -1){
		switch(opt){
			case 'd': flags[0] = 1; break;
			case 'h': flags[1] = 1; break;
			case 'o': flags[2] = 1; break;
			default :
				  fprintf(stderr, "%s", usage());
				  return 1;
		}
	}

	if(argc > 2){
		int i;
		for(i = 0; i < 3; i++){
			if(flags[i] == 1){
				for(index = optind; index < argc; index++){
					(fun_ptr[i]) (argv[index]);
					putchar('\n');
				}
			}
		}
	}
	else if(optind == 2){
		int c, i;
		while((c = getchar()) != EOF){
			for(i = 0; i < 3; i++){
				if(flags[i] == 1){
					(fun_ptr[i]) ( (char*) &c );
				}
			}
		}
		putchar('\n');
	}
	else{
		fprintf(stderr, "%s", usage());
	}

	return 0;
}

void dec(char* string){
	int i, j = 0;
	for(i = strlen(string); j < i; j++){
		printf("%d ", string[j]);
	}
}

void hex(char* string){
	int i, j = 0;
	for(i = strlen(string); j < i; j++){
		printf("%x ", string[j]);
	}
}

void oct(char* string){
	int i, j = 0;
	for(i = strlen(string); j < i; j++){
		printf("%o ", string[j]);
	}
}

char* usage(){
	return "Usage: ascii [options] [string]\nDec Hex    Dec Hex    Dec Hex  Dec Hex  Dec Hex  Dec Hex   Dec Hex   Dec Hex\n  0 00 NUL  16 10 DLE  32 20    48 30 0  64 40 @  80 50 P   96 60 `  112 70 p\n  1 01 SOH  17 11 DC1  33 21 !  49 31 1  65 41 A  81 51 Q   97 61 a  113 71 q\n  2 02 STX  18 12 DC2  34 22 \"  50 32 2  66 42 B  82 52 R   98 62 b  114 72 r\n  3 03 ETX  19 13 DC3  35 23 #  51 33 3  67 43 C  83 53 S   99 63 c  115 73 s\n  4 04 EOT  20 14 DC4  36 24 $  52 34 4  68 44 D  84 54 T  100 64 d  116 74 t\n  5 05 ENQ  21 15 NAK  37 25 %  53 35 5  69 45 E  85 55 U  101 65 e  117 75 u\n  6 06 ACK  22 16 SYN  38 26 &  54 36 6  70 46 F  86 56 V  102 66 f  118 76 v\n  7 07 BEL  23 17 ETB  39 27 '  55 37 7  71 47 G  87 57 W  103 67 g  119 77 w\n  8 08 BS   24 18 CAN  40 28 (  56 38 8  72 48 H  88 58 X  104 68 h  120 78 x\n  9 09 HT   25 19 EM   41 29 )  57 39 9  73 49 I  89 59 Y  105 69 i  121 79 y\n 10 0A LF   26 1A SUB  42 2A *  58 3A :  74 4A J  90 5A Z  106 6A j  122 7A z\n 11 0B VT   27 1B ESC  43 2B +  59 3B ;  75 4B K  91 5B [  107 6B k  123 7B {\n 12 0C FF   28 1C FS   44 2C ,  60 3C <  76 4C L  92 5C \\  108 6C l  124 7C |\n 13 0D CR   29 1D GS   45 2D -  61 3D =  77 4D M  93 5D ]  109 6D m  125 7D }\n 14 0E SO   30 1E RS   46 2E .  62 3E >  78 4E N  94 5E ^  110 6E n  126 7E ~\n 15 0F SI   31 1F US   47 2F /  63 3F ?  79 4F O  95 5F _  111 6F o  127 7F DEL\nOptions are:\n  -h = Hexadecimal values\n  -d = Decimal values\n  -o = Octal values\n";
}