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// A small "cat" utility that copies stdin to stdout.
// It does only one 4K read from stdin, and writes it to stdout in as few
// write()s as possible.
// This gives a controlled number of operations, which makes testing the
// random operations more robust.
#include <stdio.h> // printf(), perror()
#include <unistd.h> // read(), write()
const size_t BUFSIZE = 4092;
int main(void)
{
char buf[BUFSIZE];
ssize_t r, w, pos;
r = read(0, buf, BUFSIZE);
if (r < 0) {
perror("Read error in small-cat");
return 1;
}
pos = 0;
while (r > 0) {
w = write(1, buf + pos, r);
if (w <= 0) {
perror("Write error in small-cat");
return 2;
}
pos += w;
r -= w;
}
return 0;
}
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