1 #include <stdarg.h> 2 #include <stdio.h> 3 #include <stdlib.h> 4 #include <bufprintf.h> 5 6 int vbufprintf(struct print_buf *buf, const char *format, va_list ap) 7 { 8 va_list ap2; 9 int rv; 10 11 va_copy(ap2, ap); 12 rv = vsnprintf(NULL, 0, format, ap); 13 14 /* >= to make sure we have space for terminating null */ 15 if (rv + buf->len >= buf->size) { 16 size_t newsize = rv + buf->len + BUFPAD; 17 char *newbuf; 18 19 newbuf = realloc(buf->buf, newsize); 20 if (!newbuf) { 21 rv = -1; 22 goto bail; 23 } 24 25 buf->buf = newbuf; 26 buf->size = newsize; 27 } 28 29 rv = vsnprintf(buf->buf + buf->len, buf->size - buf->len, format, ap2); 30 buf->len += rv; 31 bail: 32 va_end(ap2); 33 return rv; 34 } 35 36 int bufprintf(struct print_buf *buf, const char *format, ...) 37 { 38 va_list ap; 39 int rv; 40 41 va_start(ap, format); 42 rv = vbufprintf(buf, format, ap); 43 va_end(ap); 44 return rv; 45 } 46
