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// Author Name: Matt Strapp
// Date: 2022-01-26
// x500: strap012
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int IPv4ToInt(char *ipv4, int isBigEndian) {
unsigned int ipv4Int = 0;
short int i = 0;
char *chunk = strtok(ipv4, ".");
while (chunk != NULL) {
int ipv4Segment = atoi(chunk);
if (ipv4Segment > 255 || ipv4Segment < 0) {
printf("ERROR\n");
exit(0);
}
ipv4Int = (isBigEndian) ? (ipv4Int << 8) | ipv4Segment
: (ipv4Int >> 8) + (ipv4Segment << 24);
i++;
chunk = strtok(NULL, ".");
}
if (i != 4) {
printf("ERROR\n");
exit(0);
}
return ipv4Int;
}
char *IntToIPv4(long ipv4_int, int isBigEndian) {
if (ipv4_int > 4294967295 || ipv4_int < 0) {
printf("ERROR\n");
exit(0);
}
char *ipv4 = (char *)calloc(16, sizeof(char));
int i = 0;
while (i < 4) {
int ipv4Segment = (isBigEndian) ? (ipv4_int >> (8 * (3 - i))) & 255
: (ipv4_int >> (8 * i)) & 255;
sprintf(ipv4 + strlen(ipv4), "%d", ipv4Segment);
if (i != 3)
sprintf(ipv4 + strlen(ipv4), ".");
i++;
}
return ipv4;
}
int main(int argc, char **argv) {
int toHuman = atoi(argv[1]);
int isBigEndian = atoi(argv[3]);
if (toHuman) {
long toIpv4 = strtol(argv[2], NULL, 10);
char *ret = IntToIPv4(toIpv4, isBigEndian);
printf("%s\n", ret);
free(ret);
} else {
unsigned int ret = IPv4ToInt(argv[2], isBigEndian);
printf("%u\n", ret);
return 0;
}
}
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