/* * Unreal Internet Relay Chat Daemon, src/ircsprintf.c * * (C) Copyright 2013 * * Author: Falcon Darkstar Momot based upon earlier code by Carlo Wood in 1997: * 1024/624ACAD5 1997/01/26 Carlo Wood, Run on IRC * Key fingerprint = 32 EC A7 B6 AC DB 65 A6 F6 F6 55 DD 1C DC FF 61 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2, or (at your option) * any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * * $Id$ */ #include "ircsprintf.h" #include /** Optimized version of vsnprintf() for us. * ircvsnprintf is optimized for the formats: %s, %c, %d, %i, %u, %lu and %lld. * If you only use these format string types then this function is significantly * faster than regular vsnprintf(). * When it encounters any other format type or things like padding, precision, * etc. then it will resort to calling vsnprintf(), so no problem. */ char *ircvsnprintf(char *str, size_t size, const char *format, va_list vl) { char *str_begin = str; char c; const char *end = str+size-1; /* for comparison, not dereferencing. It is the last position a null can go. */ char scratch_buffer[32]; /* large enough for 64 bit integer as a string */ if (!size) return str; while (str!=end && (c = *format++)) { if (c == '%') { c = *format++; if (c == 's') { /* %s - string */ const char *p1 = va_arg(vl, const char *); while (str!=end && *p1) *str++ = *p1++; continue; } else if (c == 'c') { /* %c - single character */ *str++ = (char)va_arg(vl, int); continue; } else if (c == 'd' || c == 'i') { /* %d and %i - integer */ char *t; int v = va_arg(vl, int); int i = 0; size_t len; if (v<0) { v*=-1; *str++ = '-'; if (str==end) break; } if (v==0) { *str++ = '0'; continue; } t = scratch_buffer + sizeof(scratch_buffer); while (v) { *--t = (v%10) + '0'; v/=10; } len = sizeof(scratch_buffer)-(t-scratch_buffer); if ((str+len)>end) break; for (i = 0; i < len; i++) *str++=t[i]; continue; } else if (c == 'l') { if (format[0] == 'l' && format[1] == 'd') { /* %lld - long long */ char *t; long long v = va_arg(vl, long long); int i = 0; size_t len; format += 2; if (v<0) { v*=-1; *str++ = '-'; if (str==end) break; } if (v==0) { *str++ = '0'; continue; } t = scratch_buffer + sizeof(scratch_buffer); while (v) { *--t = (v%10) + '0'; v/=10; } len = sizeof(scratch_buffer)-(t-scratch_buffer); if ((str+len)>end) break; for (i = 0; i < len; i++) *str++=t[i]; continue; } if (*format == 'u') { /* %lu - unsigned long */ char *t; unsigned long v = va_arg(vl, unsigned long); int i = 0; size_t len; format++; if (v==0) { *str++ = '0'; continue; } t = scratch_buffer + sizeof(scratch_buffer); while (v) { *--t = (v%10) + '0'; v/=10; } len = sizeof(scratch_buffer)-(t-scratch_buffer); if ((str+len)>end) break; for (i = 0; i < len; i++) *str++=t[i]; continue; } } else if (c == 'u') { /* %u - unsigned integer */ char *t; unsigned int v = va_arg(vl, unsigned int); int i = 0; size_t len; if (v==0) { *str++ = '0'; continue; } t = scratch_buffer + sizeof(scratch_buffer); while (v) { *--t = (v%10) + '0'; v/=10; } len = sizeof(scratch_buffer)-(t-scratch_buffer); if ((str+len)>end) break; for (i = 0; i < len; i++) *str++=t[i]; continue; } else if (c == '%') { /* %% - literal percent character */ *str++ = '%'; continue; } else if (!c) break; /* A % at the end of the format string (illegal, skipped) */ /* The default case, when we cannot handle the % format: * Stop what we are doing and pass control to the real vsnprintf() */ format -= 2; vsnprintf(str, (size_t)(end-str+1), format, vl); return str_begin; } *str++ = c; } *str = 0; return str_begin; } char *ircsnprintf(char *str, size_t size, const char *format, ...) { va_list vl; char *ret; va_start(vl, format); ret = ircvsnprintf(str, size, format, vl); va_end(vl); return ret; }