mirror of https://github.com/fhem/fhem-mirror.git
95 lines
1.8 KiB
C
95 lines
1.8 KiB
C
/*
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Four2hex was written to convert the housecode based on digits ranging from 1
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to 4 into hex code and vica versa.
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Four2hex is freeware based on the GNU Public license.
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To built it:
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$ make four2hex
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Install it to /usr/local/bin:
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$ su
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# make install
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Here an example from "four"-based to hex:
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$ four2hex 12341234
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1b1b
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Here an example in the other (reverse) direction:
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$ four2hex -r 1b1b
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12341234
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Enjoy.
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Peter Stark, (Peter dot stark at t-online dot de)
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*/
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#include <stdio.h>
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#include <ctype.h>
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int atoh (const char c)
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{
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int ret=0;
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ret = (int) (c - '0');
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if (ret > 9) {
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ret = (int) (c - 'a' + 10);
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}
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return ret;
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}
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int strlen(const char *);
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main (int argc, char **argv)
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{
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char c, *s, *four;
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long int result;
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int b, i, h;
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if (argc < 2 || argc >3) {
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fprintf (stderr, "usage: four2hex four-string\n");
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fprintf (stderr, " or: four2hex -r hex-string\n");
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return (1);
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}
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result = 0L;
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if (strcmp(argv[1], "-r") == 0) {
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/* reverse (hex->4) */
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for (s = argv[2]; *s != '\0'; s++) {
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c = tolower(*s);
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b = atoh(c);
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for (i = 0; i < 2; i++) {
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h = ((b & 0xc) >> 2) + 1;
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b = (b & 0x3) << 2;
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printf ("%d", h);
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}
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}
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printf ("\n");
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} else {
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/* normal (4->hex) */
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four = argv[1];
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if (strlen(four) == 4 || strlen(four) == 8) {
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for (s = four; *s != '\0'; s++) {
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result = result << 2;
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switch (*s) {
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case '1' : result = result + 0; break;
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case '2' : result = result + 1; break;
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case '3' : result = result + 2; break;
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case '4' : result = result + 3; break;
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default :
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fprintf (stderr, "four-string may contain '1' to '4' only\n");
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break;
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}
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}
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if (strlen(four) == 8) {
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printf ("%04x\n", result);
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} else {
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printf ("%02x\n", result);
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}
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} else {
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fprintf (stderr, "four-string must be of length 4 or 8\n");
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return (1);
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}
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}
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return (0);
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}
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