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2 months ago
/*
* UCW Library -- A simple growing buffers for byte-sized items
*
* (c) 2006 Pavel Charvat <pchar@ucw.cz>
*
* This software may be freely distributed and used according to the terms
* of the GNU Lesser General Public License.
*/
#include <ucw/lib.h>
#include <ucw/bbuf.h>
#include <stdio.h>
char *
bb_vprintf_at(bb_t *bb, size_t ofs, const char *fmt, va_list args)
{
bb_grow(bb, ofs + 1);
va_list args2;
va_copy(args2, args);
int cnt = vsnprintf(bb->ptr + ofs, bb->len - ofs, fmt, args2);
va_end(args2);
if (cnt < 0)
{
/* Our C library doesn't support C99 return value of vsnprintf, so we need to iterate */
do
{
bb_do_grow(bb, bb->len + 1);
va_copy(args2, args);
cnt = vsnprintf(bb->ptr + ofs, bb->len - ofs, fmt, args2);
va_end(args2);
}
while (cnt < 0);
}
else if ((uint)cnt >= bb->len - ofs)
{
bb_do_grow(bb, ofs + cnt + 1);
va_copy(args2, args);
int cnt2 = vsnprintf(bb->ptr + ofs, bb->len - ofs, fmt, args2);
va_end(args2);
ASSERT(cnt2 == cnt);
}
return bb->ptr + ofs;
}
char *
bb_printf_at(bb_t *bb, size_t ofs, const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
char *res = bb_vprintf_at(bb, ofs, fmt, args);
va_end(args);
return res;
}
char *
bb_vprintf(bb_t *bb, const char *fmt, va_list args)
{
return bb_vprintf_at(bb, 0, fmt, args);
}
char *
bb_printf(bb_t *bb, const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
char *res = bb_vprintf_at(bb, 0, fmt, args);
va_end(args);
return res;
}
#ifdef TEST
int main(void)
{
bb_t bb;
bb_init(&bb);
char *x = bb_printf(&bb, "<Hello, %s!>", "World");
fputs(x, stdout);
x = bb_printf_at(&bb, 5, "<Hello, %50s!>\n", "World");
fputs(x, stdout);
bb_done(&bb);
return 0;
}
#endif