1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <string.h>
4
5
6 typedef struct _Buffer {
7 char *buff;
8 int room, used;
9 } Buffer;
10
11 void InitBuffer (Buffer *b);
12 void AppendToBuffer (Buffer *b, const char *str, int len);
13 void ReadFile (Buffer *buffer, FILE *input);
14
15 #define INIT_BUFFER_SIZE 10000
16
17 void
InitBuffer(Buffer * b)18 InitBuffer (Buffer *b)
19 {
20 b->room = INIT_BUFFER_SIZE;
21 b->used = 0;
22 b->buff = (char *)malloc(INIT_BUFFER_SIZE*sizeof(char));
23 }
24
25 void
AppendToBuffer(Buffer * b,const char * str,int len)26 AppendToBuffer (Buffer *b, const char *str, int len)
27 {
28 while (b->used + len > b->room) {
29 b->buff = (char *)realloc(b->buff, 2*b->room*(sizeof(char)));
30 b->room *= 2;
31 }
32 strncpy(b->buff + b->used, str, len);
33 b->used += len;
34 }
35
36 void
ReadFile(Buffer * buffer,FILE * input)37 ReadFile (Buffer *buffer, FILE *input)
38 {
39 char buf[BUFSIZ + 1];
40 int bytes;
41
42 buffer->used = 0;
43 while (!feof(input) && (bytes = fread(buf, 1, BUFSIZ, input)) > 0) {
44 AppendToBuffer(buffer, buf, bytes);
45 }
46 AppendToBuffer(buffer, "", 1);
47 }
48
49 int
main(int argc,char * argv[])50 main(int argc, char *argv[])
51 {
52 char filename[] = "xbug.c";
53 FILE *input;
54 Buffer buffer;
55
56 InitBuffer(&buffer);
57
58 if (!freopen (filename, "r", stdin))
59 fprintf(stderr, "cannot open file\n");
60
61 unsetenv ("LD_LIBRARY_PATH");
62
63 if (!(input = popen("/bin/cat", "r")))
64 fprintf(stderr, "cannot run \n");
65
66 ReadFile(&buffer, input);
67 pclose(input);
68
69 return 0;
70 }
71