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/*
* snprintf() and vsnprintf() functions for the Fast Light Tool Kit (FLTK).
*
* Copyright 1998-2010 by Bill Spitzak and others.
*
* This library is free software. Distribution and use rights are outlined in
* the file "COPYING" which should have been included with this file. If this
* file is missing or damaged, see the license at:
*
* https://www.fltk.org/COPYING.php
*
* Please see the following page on how to report bugs and issues:
*
* https://www.fltk.org/bugs.php
*/
#include <stdio.h>
#include "flstring.h"
#ifdef HAVE_SYS_STDTYPES_H
# include <sys/stdtypes.h>
#endif /* HAVE_SYS_STDTYPES_H */
#ifdef __cplusplus
extern "C" {
#endif
/**
\file vsnprintf.c
\brief Portable vsnprintf() implementation.
*/
/**
FLTK's platform independent wrapper for the vsnprintf() C library function.
This function guarantees:
- access to vsnprintf(), even on systems that don't have it (FLTK's own
built-in code is used)
- Guarantees NUL termination. Even if string expands larger than the buffer,
a terminating NUL is included, unlike some implementations of vsnprintf(),
notably Microsoft Visual Studio (pre-2015), which can leave the string
unterminated when truncated.
If the build environment for FLTK has vsnprintf(), fl_vsnprintf()
is just a wrapper around the compiler's provided function. Otherwise,
if the function is NOT available, FLTK's own built-in version is provided.
The FLTK built in provides these style options:
- %[ -+#']
- * -- padding width
- .* -- precision width
- Data types: h, l, ll, L
- Floating point formats: E, G, e, f, g
- Integer formats: B, X, b, d, i, o, u, x
- Pointer format: p
- String/char: c, s, n
*/
int fl_vsnprintf(char* buffer, size_t bufsize, const char* format, va_list ap) {
#if defined(HAVE_VSNPRINTF) && defined(__linux__)
return vsnprintf(buffer, bufsize, format, ap);
#else
char *bufptr, /* Pointer to position in buffer */
*bufend, /* Pointer to end of buffer */
sign, /* Sign of format width */
size, /* Size character (h, l, L) */
type; /* Format type character */
int width, /* Width of field */
prec; /* Number of characters of precision */
char tformat[100], /* Temporary format string for sprintf() */
*tptr, /* Pointer into temporary format */
temp[1024]; /* Buffer for formatted numbers */
char *s; /* Pointer to string */
int slen; /* Length of string */
int bytes; /* Total number of bytes needed */
/*
* Loop through the format string, formatting as needed...
*/
bufptr = buffer;
bufend = buffer + bufsize - 1;
bytes = 0;
while (*format) {
if (*format == '%') {
tptr = tformat;
*tptr++ = *format++;
if (*format == '%') {
if (bufptr && bufptr < bufend) *bufptr++ = *format;
bytes ++;
format ++;
continue;
} else if (strchr(" -+#\'", *format)) {
*tptr++ = *format;
sign = *format++;
} else sign = 0;
if (*format == '*') {
/* Get width from argument... */
format ++;
width = va_arg(ap, int);
snprintf(tptr, sizeof(tformat) - (tptr - tformat), "%d", width);
tptr += strlen(tptr);
} else {
width = 0;
while (isdigit(*format & 255)) {
if (tptr < (tformat + sizeof(tformat) - 1)) *tptr++ = *format;
width = width * 10 + *format++ - '0';
}
}
if (*format == '.') {
if (tptr < (tformat + sizeof(tformat) - 1)) *tptr++ = *format;
format ++;
if (*format == '*') {
/* Get precision from argument... */
format ++;
prec = va_arg(ap, int);
snprintf(tptr, sizeof(tformat) - (tptr - tformat), "%d", prec);
tptr += strlen(tptr);
} else {
prec = 0;
while (isdigit(*format & 255)) {
if (tptr < (tformat + sizeof(tformat) - 1)) *tptr++ = *format;
prec = prec * 10 + *format++ - '0';
}
}
} else prec = -1;
size = '\0';
if (*format == 'l' && format[1] == 'l') {
size = 'L';
if (tptr < (tformat + sizeof(tformat) - 2)) {
*tptr++ = 'l';
*tptr++ = 'l';
}
format += 2;
} else if (*format == 'h' || *format == 'l' || *format == 'L') {
if (tptr < (tformat + sizeof(tformat) - 1)) *tptr++ = *format;
size = *format++;
}
if (!*format) break;
if (tptr < (tformat + sizeof(tformat) - 1)) *tptr++ = *format;
type = *format++;
*tptr = '\0';
switch (type) {
case 'E' : /* Floating point formats */
case 'G' :
case 'e' :
case 'f' :
case 'g' :
if ((width + 2) > (int)sizeof(temp)) break;
sprintf(temp, tformat, va_arg(ap, double));
bytes += (int) strlen(temp);
if (bufptr) {
if ((bufptr + strlen(temp)) > bufend) {
strncpy(bufptr, temp, (size_t)(bufend - bufptr));
bufptr = bufend;
} else {
strcpy(bufptr, temp);
bufptr += strlen(temp);
}
}
break;
case 'B' : /* Integer formats */
case 'X' :
case 'b' :
case 'd' :
case 'i' :
case 'o' :
case 'u' :
case 'x' :
if ((width + 2) > (int)sizeof(temp)) break;
#ifdef HAVE_LONG_LONG
if (size == 'L')
sprintf(temp, tformat, va_arg(ap, long long));
else
#endif /* HAVE_LONG_LONG */
if (size == 'l')
sprintf(temp, tformat, va_arg(ap, long));
else
sprintf(temp, tformat, va_arg(ap, int));
bytes += (int) strlen(temp);
if (bufptr) {
if ((bufptr + strlen(temp)) > bufend) {
strncpy(bufptr, temp, (size_t)(bufend - bufptr));
bufptr = bufend;
} else {
strcpy(bufptr, temp);
bufptr += strlen(temp);
}
}
break;
case 'p' : /* Pointer value */
if ((width + 2) > (int)sizeof(temp)) break;
sprintf(temp, tformat, va_arg(ap, void *));
bytes += (int) strlen(temp);
if (bufptr) {
if ((bufptr + strlen(temp)) > bufend) {
strncpy(bufptr, temp, (size_t)(bufend - bufptr));
bufptr = bufend;
} else {
strcpy(bufptr, temp);
bufptr += strlen(temp);
}
}
break;
case 'c' : /* Character or character array */
bytes += width;
if (bufptr) {
if (width <= 1) *bufptr++ = va_arg(ap, int);
else {
if ((bufptr + width) > bufend) width = (int) (bufend - bufptr);
memcpy(bufptr, va_arg(ap, char *), (size_t)width);
bufptr += width;
}
}
break;
case 's' : /* String */
if ((s = va_arg(ap, char *)) == NULL) s = "(null)";
slen = (int) strlen(s);
if (slen > width && prec != width) width = slen;
bytes += width;
if (bufptr) {
if ((bufptr + width) > bufend) width = (int) (bufend - bufptr);
if (slen > width) slen = width;
if (sign == '-') {
strncpy(bufptr, s, (size_t)slen);
memset(bufptr + slen, ' ', (size_t)(width - slen));
} else {
memset(bufptr, ' ', (size_t)(width - slen));
strncpy(bufptr + width - slen, s, (size_t)slen);
}
bufptr += width;
}
break;
case 'n' : /* Output number of chars so far */
*(va_arg(ap, int *)) = bytes;
break;
}
} else {
bytes ++;
if (bufptr && bufptr < bufend) *bufptr++ = *format;
format ++;
}
}
/*
* Nul-terminate the string and return the number of characters needed.
*/
if (bufptr) *bufptr = '\0';
return (bytes);
#endif /* HAVE_VSNPRINTF */
}
int fl_snprintf(char* str, size_t size, const char* fmt, ...) {
int ret;
va_list ap;
va_start(ap, fmt);
ret = vsnprintf(str, size, fmt, ap);
va_end(ap);
return ret;
}
#ifdef __cplusplus
}
#endif