1 #include <u.h> 2 #include <libc.h> 3 #include <bio.h> 4 #include "String.h" 5 6 enum 7 { 8 Minread= 256, 9 }; 10 11 /* Append up to 'len' input bytes to the string 'to'. 12 * 13 * Returns the number of characters read. 14 */ 15 extern int s_read(Biobuf * fp,String * to,int len)16s_read(Biobuf *fp, String *to, int len) 17 { 18 int rv; 19 int n; 20 21 if(to->ref > 1) 22 sysfatal("can't s_read a shared string"); 23 for(rv = 0; rv < len; rv += n){ 24 n = to->end - to->ptr; 25 if(n < Minread){ 26 s_grow(to, Minread); 27 n = to->end - to->ptr; 28 } 29 if(n > len - rv) 30 n = len - rv; 31 n = Bread(fp, to->ptr, n); 32 if(n <= 0) 33 break; 34 to->ptr += n; 35 } 36 s_terminate(to); 37 return rv; 38 } 39