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author | Mole Shang <[email protected]> | 2024-01-17 11:33:39 +0800 |
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committer | Mole Shang <[email protected]> | 2024-01-17 11:33:39 +0800 |
commit | daa90a639a35e9f99747c92bb28946ac414615bd (patch) | |
tree | cc119f4e037015b2fdff2b4ed8d989b8db66e3b0 /user/primes.c | |
parent | c424f997808269559f7968c812860fd1f1974a13 (diff) | |
download | xv6-labs-util.tar.gz xv6-labs-util.tar.bz2 xv6-labs-util.zip |
lab util: finishutil
Diffstat (limited to 'user/primes.c')
-rw-r--r-- | user/primes.c | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/user/primes.c b/user/primes.c new file mode 100644 index 0000000..b359524 --- /dev/null +++ b/user/primes.c @@ -0,0 +1,74 @@ +#include "kernel/types.h" +#include "user/user.h" + +#define MAX 36 +#define FIRST_PRIME 2 + +int +generate_natural(); // -> out_fd +int +prime_filter(int in_fd, int prime); // -> out_fd + +int +main(int argc, char* argv[]) +{ + int prime; + + int in = generate_natural(); + while (read(in, &prime, sizeof(int))) { + // printf("prime %d: in_fd: %d\n", prime, in); // debug + printf("prime %d\n", prime); + in = prime_filter(in, prime); + } + + close(in); + + exit(0); +} + +int +generate_natural() +{ + int out_pipe[2]; + + pipe(out_pipe); + + if (!fork()) { + for (int i = FIRST_PRIME; i < MAX; i++) { + write(out_pipe[1], &i, sizeof(int)); + } + close(out_pipe[1]); + + exit(0); + } + + close(out_pipe[1]); + + return out_pipe[0]; +} + +int +prime_filter(int in_fd, int prime) +{ + int num; + int out_pipe[2]; + + pipe(out_pipe); + + if (!fork()) { + while (read(in_fd, &num, sizeof(int))) { + if (num % prime) { + write(out_pipe[1], &num, sizeof(int)); + } + } + close(in_fd); + close(out_pipe[1]); + + exit(0); + } + + close(in_fd); + close(out_pipe[1]); + + return out_pipe[0]; +} |