1 /*! cc -o tee tee.c */

2 #include <stdio.h>

3 #include <stdlib.h>

4 #include <string.h>

5 #include <errno.h>

6

7 void output(FILE **farr, int count, char *data, size_t bytes);

8

9 int main(int argc, char **argv)

10 {

11 char buf[512];

12 size_t rdbytes;

13 FILE **files;

14 int i, fnum = 0;

15

16 if(!(files = malloc((argc - 1) * sizeof *files))) {

17 perror("malloc failed");

18 return EXIT_FAILURE;

19 }

20

21 for(i=1; i<argc; i++) {

22 if(!(files[fnum] = fopen(argv[i], "wb"))) {

23 fprintf(stderr, "failed to write to %s: %s\n", argv[i], strerror(errno));

24 } else {

25 fnum++;

26 }

27 }

28

29 while((rdbytes = fread(buf, 1, sizeof buf, stdin))) {

30 output(files, fnum, buf, rdbytes);

31 }

32

33 for(i=0; i<fnum; i++) {

34 fclose(files[i]);

35 }

36 return 0;

37 }

38

39 void output(FILE **farr, int count, char *data, size_t bytes)

40 {

41 int i;

42

43 fwrite(data, 1, bytes, stdout);

44 for(i=0; i<count; i++) {

45 fwrite(data, 1, bytes, farr[i]);

46 }

47 }