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Diffstat (limited to 'qprintf.c')
| -rw-r--r-- | qprintf.c | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/qprintf.c b/qprintf.c new file mode 100644 index 0000000..735dabe --- /dev/null +++ b/qprintf.c @@ -0,0 +1,260 @@ +/* $Id: qprintf.c 918 2008-12-31 06:07:29Z michael $ + * $URL: https://ssl.bulix.org/svn/lcd4linux/trunk/qprintf.c $ + * + * simple but quick snprintf() replacement + * + * Copyright (C) 2004 Michael Reinelt <michael@reinelt.co.at> + * Copyright (C) 2004 The LCD4Linux Team <lcd4linux-devel@users.sourceforge.net> + * + * derived from a patch from Martin Hejl which is + * Copyright (C) 2003 Martin Hejl (martin@hejl.de) + * + * This file is part of LCD4Linux. + * + * LCD4Linux 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. + * + * LCD4Linux 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. + * + */ + +/* + * exported functions: + * + * int qprintf(char *str, size_t size, const char *format, ...) + * works like snprintf(), but format only knows about %d, %x, %u and %s + * and for the numbers an optional length like %<len>d. If <len> beginns + * with '0' the free space is filled with '0's, otherwise with ' ' + */ + + +#include "config.h" + +#include <stdlib.h> +#include <stdio.h> +#include <stdarg.h> +#include <string.h> + +static char *itoa(char *buffer, const size_t size, int value, unsigned int fixedlen, unsigned int fill0) +{ + char *p; + int sign; + + /* sanity checks */ + if (buffer == NULL || size < 2) + return (NULL); + + /* remember sign of value */ + sign = 0; + if (value < 0) { + sign = 1; + if (fill0) + fixedlen -= 1; + value = -value; + } + + /* p points to last char */ + p = buffer + size - 1; + + /* set terminating zero */ + *p = '\0'; + + do { + *--p = value % 10 + '0'; + value = value / 10; + } while (value != 0 && p > buffer); + + if (sign && !fill0 && p > buffer) + *--p = '-'; + + /* fill fixed length */ + while (p > buffer && strlen(p) < fixedlen) { + if (fill0) { + *--p = '0'; + } else { + *--p = ' '; + } + } + + if (sign && fill0 && p > buffer) + *--p = '-'; + + return p; +} + + +static char *utoa(char *buffer, const size_t size, unsigned int value, unsigned int fixedlen, unsigned int fill0) +{ + char *p; + + /* sanity checks */ + if (buffer == NULL || size < 2) + return (NULL); + + /* p points to last char */ + p = buffer + size - 1; + + /* set terminating zero */ + *p = '\0'; + + do { + *--p = value % 10 + '0'; + value = value / 10; + } while (value != 0 && p > buffer); + + /* fill fixed length */ + while (p > buffer && strlen(p) < fixedlen) { + if (fill0) { + *--p = '0'; + } else { + *--p = ' '; + } + } + + return p; +} + + +static char *utox(char *buffer, const size_t size, unsigned int value, unsigned int fixedlen, unsigned int fill0) +{ + char *p; + int digit; + + /* sanity checks */ + if (buffer == NULL || size < 2) + return (NULL); + + /* p points to last char */ + p = buffer + size - 1; + + /* set terminating zero */ + *p = '\0'; + + do { + digit = value % 16; + value = value / 16; + *--p = (digit < 10 ? '0' : 'a' - 10) + digit; + } while (value != 0 && p > buffer); + + /* fill fixed length */ + while (p > buffer && strlen(p) < fixedlen) { + if (fill0) { + *--p = '0'; + } else { + *--p = ' '; + } + } + + return p; +} + + +/*! + @function qprintf + @abstract quick print values into string + @discussion similar to snprintf(), but only support for "%s", "%d", "%u", "%x" with optional length for the numbers + like "%5d" (filled with ' ') or "%05x" (filled with '0') + @param str destination + @param size maximum length of destination string + @param format (like printf() with reduced number of formats) + @result length of produced string +*/ +int qprintf(char *str, const size_t size, const char *format, ...) +{ + + va_list ap; + const char *src; + char *dst; + unsigned int len; + + src = format; + dst = str; + len = 0; + + va_start(ap, format); + + /* use size-1 for terminating zero */ + while (len < size - 1) { + + if (*src == '%') { + char buf[12], *s; + int d; + unsigned int u; + unsigned int fixedlen = 0; + unsigned int fill0 = 0; + + if (*++src == '0') + fill0 = 1; + while (*src >= '0' && *src <= '9') { + fixedlen = fixedlen * 10 + (*src - '0'); + src++; + } + + switch (*src) { + case 's': + src++; + s = va_arg(ap, char *); + while (len < size - 1 && *s != '\0') { + len++; + *dst++ = *s++; + } + break; + case 'd': + src++; + d = va_arg(ap, int); + s = itoa(buf, sizeof(buf), d, fixedlen, fill0); + while (len < size && *s != '\0') { + len++; + *dst++ = *s++; + } + break; + case 'u': + src++; + u = va_arg(ap, unsigned int); + s = utoa(buf, sizeof(buf), u, fixedlen, fill0); + while (len < size - 1 && *s != '\0') { + len++; + *dst++ = *s++; + } + break; + case 'x': + src++; + u = va_arg(ap, unsigned int); + s = utox(buf, sizeof(buf), u, fixedlen, fill0); + while (len < size - 1 && *s != '\0') { + len++; + *dst++ = *s++; + } + break; + default: + len++; + *dst++ = '%'; + } + } else { + len++; + *dst++ = *src; + if (*src++ == '\0') + break; + } + } + + va_end(ap); + + /* enforce terminating zero */ + if (len >= size - 1 && *(dst - 1) != '\0') { + len++; + *dst = '\0'; + } + + /* do not count terminating zero */ + return len - 1; +} |