#define _GNU_SOURCE /* For getopt_long */
#include <getopt.h>
-const struct option options[] =
-{
- { "hexadecimal", 0, NULL, 'x' },
- { "decimal", 0, NULL, 'd' },
- { "dotted-quad", 0, NULL, 'd' },
- { "full-output", 0, NULL, 'f' },
- { "name", 0, NULL, 'n' },
- { "help", 0, NULL, 'h' },
- { NULL, 0, NULL, 0 }
+const struct option options[] = {
+ {"hexadecimal", 0, NULL, 'x'},
+ {"decimal", 0, NULL, 'd'},
+ {"dotted-quad", 0, NULL, 'd'},
+ {"full-output", 0, NULL, 'f'},
+ {"name", 0, NULL, 'n'},
+ {"help", 0, NULL, 'h'},
+ {NULL, 0, NULL, 0}
};
const char *program;
void usage(int exit_code)
{
- fprintf(stderr, "Usage: %s [-dxnf] hostname/ip...\n", program);
- exit(exit_code);
+ fprintf(stderr, "Usage: %s [-dxnf] hostname/ip...\n", program);
+ exit(exit_code);
}
int main(int argc, char *argv[])
{
- int opt;
- int output = 0;
- int i;
- char *sep;
- int err = 0;
-
- struct hostent *host;
-
- program = argv[0];
-
- while ( (opt = getopt_long(argc, argv, "dxfnh", options, NULL)) != -1 ) {
- switch ( opt ) {
- case 'd':
- output |= 2; /* Decimal output */
- break;
- case 'x':
- output |= 4; /* Hexadecimal output */
- break;
- case 'n':
- output |= 1; /* Canonical name output */
- break;
- case 'f':
- output = 7; /* Full output */
- break;
- case 'h':
- usage(0);
- break;
- default:
- usage(EX_USAGE);
- break;
- }
- }
-
- if ( optind == argc )
- usage(EX_USAGE);
-
- if ( output == 0 )
- output = 7; /* Default output */
-
- for ( i = optind ; i < argc ; i++ ) {
- sep = "";
- host = gethostbyname(argv[i]);
- if ( !host ) {
- herror(argv[i]);
- err = 1;
- continue;
- }
-
- if ( host->h_addrtype != AF_INET || host->h_length != 4 ) {
- fprintf(stderr, "%s: No IPv4 address associated with name\n", argv[i]);
- err = 1;
- continue;
- }
-
- if ( output & 1 ) {
- printf("%s%s", sep, host->h_name);
- sep = " ";
+ int opt;
+ int output = 0;
+ int i;
+ char *sep;
+ int err = 0;
+
+ struct hostent *host;
+
+ program = argv[0];
+
+ while ((opt = getopt_long(argc, argv, "dxfnh", options, NULL)) != -1) {
+ switch (opt) {
+ case 'd':
+ output |= 2; /* Decimal output */
+ break;
+ case 'x':
+ output |= 4; /* Hexadecimal output */
+ break;
+ case 'n':
+ output |= 1; /* Canonical name output */
+ break;
+ case 'f':
+ output = 7; /* Full output */
+ break;
+ case 'h':
+ usage(0);
+ break;
+ default:
+ usage(EX_USAGE);
+ break;
+ }
}
- if ( output & 2 ) {
- printf("%s%u.%u.%u.%u", sep,
- ((unsigned char *)host->h_addr)[0],
- ((unsigned char *)host->h_addr)[1],
- ((unsigned char *)host->h_addr)[2],
- ((unsigned char *)host->h_addr)[3]);
- sep = " ";
+ if (optind == argc)
+ usage(EX_USAGE);
+
+ if (output == 0)
+ output = 7; /* Default output */
+
+ for (i = optind; i < argc; i++) {
+ sep = "";
+ host = gethostbyname(argv[i]);
+ if (!host) {
+ herror(argv[i]);
+ err = 1;
+ continue;
+ }
+
+ if (host->h_addrtype != AF_INET || host->h_length != 4) {
+ fprintf(stderr, "%s: No IPv4 address associated with name\n",
+ argv[i]);
+ err = 1;
+ continue;
+ }
+
+ if (output & 1) {
+ printf("%s%s", sep, host->h_name);
+ sep = " ";
+ }
+
+ if (output & 2) {
+ printf("%s%u.%u.%u.%u", sep,
+ ((unsigned char *)host->h_addr)[0],
+ ((unsigned char *)host->h_addr)[1],
+ ((unsigned char *)host->h_addr)[2],
+ ((unsigned char *)host->h_addr)[3]);
+ sep = " ";
+ }
+
+ if (output & 4) {
+ printf("%s%02X%02X%02X%02X", sep,
+ ((unsigned char *)host->h_addr)[0],
+ ((unsigned char *)host->h_addr)[1],
+ ((unsigned char *)host->h_addr)[2],
+ ((unsigned char *)host->h_addr)[3]);
+ sep = " ";
+ }
+
+ putchar('\n');
}
- if ( output & 4 ) {
- printf("%s%02X%02X%02X%02X", sep,
- ((unsigned char *)host->h_addr)[0],
- ((unsigned char *)host->h_addr)[1],
- ((unsigned char *)host->h_addr)[2],
- ((unsigned char *)host->h_addr)[3]);
- sep = " ";
- }
-
- putchar('\n');
- }
-
- return err;
+ return err;
}