mes/lib/libc.c

417 lines
6.9 KiB
C
Raw Normal View History

/* -*-comment-start: "//";comment-end:""-*-
* Mes --- Maxwell Equations of Software
* Copyright © 2016,2017 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
*
* This file is part of Mes.
*
* Mes 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.
*
* Mes 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 Mes. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdarg.h>
#include <stdlib.h>
#if POSIX
#define _GNU_SOURCE
#include <assert.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#endif // POSIX
int
isdigit (int c)
{
return (c>='0') && (c<='9');
}
int
isxdigit (int c)
{
return isdigit (c) || (c>='a') && (c<='f');
}
int
isnumber (int c, int base)
{
if (base == 2)
return (c>='0') && (c<='1');
if (base == 8)
return (c>='0') && (c<='7');
if (base == 10)
return isdigit (c);
if (base == 16)
return isxdigit (c);
}
int
abtoi (char const **p, int base)
{
char const *s = *p;
int i = 0;
int sign = 1;
if (!base) base = 10;
if (*s && *s == '-')
{
sign = -1;
s++;
}
while (isnumber (*s, base))
{
i *= base;
int m = *s > '9' ? 'a' - 10 : '0';
i += *s - m;
s++;
}
*p = s;
return i * sign;
}
int
atoi (char const *s)
{
char const *p = s;
return abtoi (&p, 0);
}
char itoa_buf[10];
char const*
itoa (int x)
{
//static char itoa_buf[10];
//char *p = buf+9;
char *p = itoa_buf;
p += 9;
*p-- = 0;
//int sign = x < 0; // FIXME
int sign = 0;
if (x < 0) sign = 1;
if (sign)
x = -x;
do
{
*p-- = '0' + (x % 10);
x = x / 10;
} while (x);
if (sign && *(p + 1) != '0')
*p-- = '-';
return p+1;
}
char const*
itoab (int x, int base)
{
//static char itoa_buf[10];
//char *p = buf+9;
char *p = itoa_buf;
p += 9;
*p-- = 0;
//int sign = x < 0; // FIXME
int sign = 0;
if (x < 0) sign = 1;
if (sign)
x = -x;
do
{
int i = x % base;
*p-- = i > 9 ? 'a' + i - 10 : '0' + i;
x = x / base;
} while (x);
if (sign && *(p + 1) != '0')
*p-- = '-';
return p+1;
}
int
fdputc (int c, int fd)
{
write (fd, (char*)&c, 1);
return 0;
}
int
fdputs (char const* s, int fd)
{
int i = strlen (s);
write (fd, s, i);
return 0;
}
#if !POSIX
///char **g_environment = 0; // FIXME: todo extern
int g_stdin = 0;
void _env ();
int
eputc (int c)
{
return fdputc (c, STDERR);
}
int
putchar (int c)
{
write (STDOUT, (char*)&c, 1);
return 0;
}
void
assert_fail (char* s)
{
eputs ("assert fail: ");
eputs (s);
eputs ("\n");
//*((int*)0) = 0;
char *fail = s;
fail = 0;
*fail = 0;
}
int ungetc_char = -1;
char ungetc_buf[2];
int
getchar ()
{
char c;
int i;
if (ungetc_char == -1)
{
int r = read (g_stdin, &c, 1);
if (r < 1) return -1;
i = c;
}
else
{
//FIXME
//i = ungetc_buf[ungetc_char--];
i = ungetc_buf[ungetc_char];
//ungetc_char--;
ungetc_char = ungetc_char - 1;
}
if (i < 0) i += 256;
return i;
}
int
fgetc (int fd)
{
char c;
int i;
int r = read (fd, &c, 1);
if (r < 1) return -1;
i = c;
return i;
}
void
free (void *ptr)
{
}
//#define assert(x) ((x) ? (void)0 : assert_fail (#x))
int
ungetc (int c, int fd)
{
//FIXME
//assert (ungetc_char < 2);
//assert (ungetc_char == -1 || ungetc_char < 2);
//FIXME
//ungetc_buf[++ungetc_char] = c;
ungetc_char++;
ungetc_buf[ungetc_char] = c;
return c;
}
int
strcmp (char const* a, char const* b)
{
while (*a && *b && *a == *b)
{
a++;b++;
}
return *a - *b;
}
char *
strcpy (char *dest, char const *src)
{
char *p = dest;
while (*src) *p++ = *src++;
*p = 0;
return dest;
}
char *g_brk = 0;
void *
malloc (size_t size)
{
if (!g_brk)
g_brk = brk (0);
if (brk (g_brk + size) == -1)
return 0;
char *p = g_brk;
g_brk += size;
return p;
}
void *
memcpy (void *dest, void const *src, size_t n)
{
char* p = dest;
char* q = src;
while (n--) *p++ = *q++;
return dest;
}
void *
realloc (void *ptr, size_t size)
{
void *new = malloc (size);
if (ptr && new)
{
memcpy (new, ptr, size);
free (ptr);
}
return new;
}
int
strncmp (char const* a, char const* b, size_t length)
{
while (*a && *b && *a == *b && --length) {a++;b++;}
return *a - *b;
}
char *
getenv (char const* s)
{
char **p = g_environment;
int length = strlen (s);
while (*p)
{
if (!strncmp (s, *p, length) && *(*p + length) == '=') return (*p + length + 1);
p++;
}
return 0;
}
int
setenv (char const* s, char const* v, int overwrite_p)
{
char **p = g_environment;
int length = strlen (s);
while (*p)
{
if (!strncmp (s, *p, length) && *(*p + length) == '=')
break;
p++;
}
char *entry = malloc (length + strlen (v) + 2);
int end_p = *p == 0;
*p = entry;
strcpy (entry, s);
strcpy (entry + length, "=");
strcpy (entry + length + 1, v);
*(entry + length + strlen (v) + 2) = 0;
if (end_p)
*++p = 0;
return 0;
}
int
vprintf (char const* format, va_list ap)
{
char const *p = format;
while (*p)
if (*p != '%')
putchar (*p++);
else
{
p++;
char c = *p;
switch (c)
{
case '%': {putchar (*p); break;}
case 'c': {char c; c = va_arg (ap, char); putchar (c); break;}
case 'd': {int d; d = va_arg (ap, int); puts (itoa (d)); break;}
case 's': {char *s; s = va_arg (ap, char *); puts (s); break;}
default: {putchar (*p); break;}
}
p++;
}
va_end (ap);
return 0;
}
int
printf (char const* format, ...)
{
va_list ap;
va_start (ap, format);
int r = vprintf (format, ap);
va_end (ap);
return r;
}
int
vsprintf (char *str, char const* format, va_list ap)
{
char const *p = format;
while (*p)
if (*p != '%')
*str++ = *p++;
else
{
p++;
char c = *p;
switch (c)
{
case '%': {*str++ = *p; break;}
case 'c': {char c; c = va_arg (ap, char); *str++ = c; break;}
case 'd': {int d; d = va_arg (ap, int); char const *s; s = itoa (d); while (*s) *str++ = *s++; break;}
case 's': {char *s; s = va_arg (ap, char *); while (*s) *str++ = *s++; break;}
default: {*str++ = *p; break;}
}
p++;
}
va_end (ap);
*str = 0;
return strlen (str);
}
int
sprintf (char *str, char const* format, ...)
{
va_list ap;
va_start (ap, format);
int r = vsprintf (str, format, ap);
va_end (ap);
return r;
}
#endif //!POSIX