FreeCalypso > hg > fc-sim-tools
view libutil/shorthand.c @ 47:b0cf75d0bb2d
doc/Serial-SIM-readers article written
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Sun, 21 Mar 2021 04:32:18 +0000 |
parents | 34bbb0585cab |
children |
line wrap: on
line source
/* * This module implements the function for parsing shorthand decimal strings. */ #include <sys/types.h> #include <ctype.h> #include <stdio.h> #include <string.h> #include <strings.h> parse_decimal_shorthand(arg, dest, maxdigits) char *arg; u_char *dest; unsigned maxdigits; { unsigned n, ntail; if (!*arg) { fprintf(stderr, "error: empty argument given for decimal string\n"); return(-1); } if (!isdigit(*arg)) { fprintf(stderr, "error: decimal string argument begins with a non-digit\n"); return(-1); } for (n = 0; isdigit(*arg); ) { if (n >= maxdigits) { toolong: fprintf(stderr, "error: decimal string exceeds limit of %u digits\n", maxdigits); return(-1); } dest[n++] = *arg++ - '0'; } if (!*arg) { if (n != maxdigits) { fprintf(stderr, "error: %u digits required, %u digits given\n", maxdigits, n); return(-1); } return(0); } if (*arg++ != '-') { malformed: fprintf(stderr, "error: malformed shorthand decimal string argument\n"); return(-1); } ntail = strlen(arg); if (n + ntail >= maxdigits) goto toolong; while (n < maxdigits - ntail) dest[n++] = 0; if (!isdigit(*arg)) goto malformed; while (*arg) { if (!isdigit(*arg)) goto malformed; dest[n++] = *arg++ - '0'; } return(0); }