clapperboard/lib/print.c

237 lines
7.9 KiB
C

/* 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 3 of the License, 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, see <http://www.gnu.org/licenses/>.
*
*/
/** printing utilities to replace the large printf from the standard library (code)
* @file print.c
* @author King Kévin <kingkevin@cuvoodoo.info>
* @date 2017
*/
/* standard libraries */
#include <stdint.h> // standard integer types
#include <stdbool.h> // boolean type
#include <stdarg.h> // variadic utilities
/* own libraries */
#include "print.h" // printing utilities
/** output \r\n (Carriage Return + Line Feed) for each \r, \n, \r\n, or \n\r for better terminal compatibility */
static const bool crlf = true;
uint8_t putc(char c)
{
uint8_t length = 0; // number of characters printed
static char newline = 0; // to remember on which character we sent the newline
if (!crlf) {
_putc(c); // print character
length++; // remember we printed 1 character
} else if ('\r' == c || '\n' == c) { // send CR+LF newline for most carriage return and line feed combination
if (0==newline || c==newline) { // send newline only if not already send (and only once on \r\n or \n\r)
_putc('\r'); // send CR
_putc('\n'); // send LF
length += 2; // remember we printed 2 characters
newline = c; // remember on which character we sent the newline
}
} else {
_putc(c); // print character
newline = 0; // clear new line
length++; // remember we printed 1 character
}
return length; // return number of characters printed
}
uint32_t puts(const char* s)
{
uint32_t length = 0; // number of characters printed
while (*s) { // stop at end of string
length += putc(*(s++)); // send character
}
return length;
}
static uint8_t print_unsigned(uint64_t u, uint8_t padding, bool sign) {
char number[20] = {0}; // construct the number in reverse order (20 chars are required to store UINT64_MAX)
uint8_t digits = 0; // to count the number of digits
uint8_t length = 0; // number of characters printed
do {
number[digits++] = '0'+(u%10); // store digit
u /= 10; // go to next digit
} while (u>0);
if (digits>sizeof(number)) { // prevent buffer underflow
return 0;
}
if (sign) { // print sign
length += putc('+'); // we only have positive numbers
}
for (uint8_t zeros = digits; zeros<padding; zeros++) { // print padding 0's
length += putc('0'); // print 0
}
for (uint8_t digit = 0; digit < digits; digit++) { // go through all digits
length += putc(number[digits-digit-1]); // print digit (in reverse order)
}
return length; // return number of characters printed
}
static uint8_t print_signed(int64_t d, uint8_t padding, bool sign) {
uint8_t length = 0; // number of characters printed
if (d<0) {
length += putc('-'); // print sign
length += print_unsigned((uint64_t)-d, padding, false); // print number (casting because there is one more negative value then positive value)
} else {
length += print_unsigned(d, padding, sign); // print number
}
return length; // return number of characters printed
}
static uint8_t print_nibble(uint8_t nibble, bool upcase) {
uint8_t length = 0; // number of characters printed
nibble &= 0x0f; // ensure we only have a nibble
if (nibble<10) {
length += putc('0'+nibble);
} else if (upcase) {
length += putc('A'+nibble-10);
} else {
length += putc('a'+nibble-10);
}
return length; // return number of characters printed
}
static uint8_t print_hex(uint32_t hex, uint8_t padding, bool prefix, bool upcase) {
uint8_t length = 0; // number of characters printed
if (prefix) { // print 0x prefix
length += putc('0');
length += putc('x');
}
uint8_t digits = 0; // number of digits to print
// figure out number of digits to print
if (hex>0x00ffffff) {
digits = 8;
} else if (hex>0x0000ffff) {
digits = 6;
} else if (hex>0x000000ff) {
digits = 4;
} else {
digits = 2;
}
for (uint8_t zeros = digits; zeros<padding; zeros++) { // print padding 0's
length += putc('0'); // print 0
}
for (uint8_t digit = 0; digit < digits; digit++) { // go through all digits
length += print_nibble(hex>>((digits-digit-1)*4), upcase); // print nibble (in reverse order)
}
return length; // return number of characters printed
}
static uint8_t print_bits(uint32_t u, uint8_t padding, bool prefix) {
char bits[32] = {0}; // construct the bit string in reverse order
uint8_t digits = 0; // to count the number of digits
uint8_t length = 0; // number of characters printed
do {
bits[digits++] = '0'+(u&0x1); // store bit
u >>= 1; // go to next bit
} while (u>0);
if (digits>sizeof(bits)) { // prevent buffer underflow
return 0;
}
if (prefix) { // print prefix
length += putc('0');
length += putc('b');
}
for (uint8_t zeros = digits; zeros<padding; zeros++) { // print padding 0's
length += putc('0'); // print 0
}
for (uint8_t digit = 0; digit < digits; digit++) { // go through all bits
length += putc(bits[digits-digit-1]); // print bit (in reverse order)
}
return length; // return number of characters printed
}
uint32_t printf(const char *fmt, ...)
{
uint32_t length = 0; // number of characters printed
uint8_t padding = 0; // number of padding 0's
bool sign = false; // if sign needs to be printed
va_list va; // variable argument list
va_start(va, fmt); // initialise variable argument list
while (*fmt) { // go through format string
padding = 0; // reset padding
sign = false; // reset sign
if ('%'!=*fmt) { // check for format specifier prefix
length += putc(*fmt++); // print character (no interpretation needed)
} else {
fmt++; // go to format specifier
if (0==*fmt) { // end of string detected
goto end;
}
// check if sign need to be printed
if ('+'==*fmt) { // sign required
sign = true; // remember sign is required
fmt++; // go to padding number
if (0==*fmt) { // end of string detected
goto end;
}
}
// check padding
if ('0'==*fmt) { // padding required
fmt++; // go to padding number
if (0==*fmt) { // end of string detected
goto end;
}
if (*fmt>='0' && *fmt<='9') {
padding = *fmt-'0';
fmt++; // go to format specifier
if (0==*fmt) { // end of string detected
goto end;
}
}
}
// check format specifier
switch (*fmt) {
case 'u': // for uint8_t, uint16_t, uint32_t, unsigned int, unsigned long
length += print_unsigned(va_arg(va,uint32_t), padding, sign);
break;
case 'U': // for uint64_t, unsigned long long
length += print_unsigned(va_arg(va,uint64_t), padding, sign);
break;
case 'd': // for int8_t, int16_t, int32_t, int, long
length += print_signed(va_arg(va,int32_t), padding, sign);
break;
case 'D': // for int64_t, long long
length += print_signed(va_arg(va,int64_t), padding, sign);
break;
case 'c': // for char, unsigned char
length += putc((char)(va_arg(va,int))); // needs casting because the returned value is promoted
break;
case 'x': // for downcase hexadecimal
length += print_hex(va_arg(va,uint32_t), padding, sign, false);
break;
case 'X': // for upcase hexadecimal
length += print_hex(va_arg(va,uint32_t), padding, sign, true);
break;
case 'b': // for bits
length += print_bits(va_arg(va,uint32_t), padding, sign);
break;
case 's': // for strings
length += puts(va_arg(va,char*));
break;
default:
length += putc(*fmt); // print character (unknown format specifier)
}
fmt++; // go to next character
}
}
end:
va_end(va);
return length;
}