diff options
Diffstat (limited to 'Year_2')
| -rw-r--r-- | Year_2/OS/filter.c | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/Year_2/OS/filter.c b/Year_2/OS/filter.c new file mode 100644 index 0000000..2312667 --- /dev/null +++ b/Year_2/OS/filter.c @@ -0,0 +1,196 @@ +#include <ctype.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/ipc.h> +#include <sys/sem.h> +#include <sys/shm.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <unistd.h> + +#define MAX_LEN 1024 + +int +WAIT(int id_sem, int n) +{ + struct sembuf sops[1] = { { n, -1, 0 } }; + + return semop(id_sem, sops, 1); +} + +int +SIGNAL(int id_sem, int n) +{ + struct sembuf sops[1] = { { n, 1, 0 } }; + + return semop(id_sem, sops, 1); +} + +void +filter(int id_shm, int id_sem, int index, int n, char* expr) +{ + char* msg; + int quit; + char* token; + int action; + char* word; + char* j; + char k[MAX_LEN]; + unsigned w; + char c[1]; + char next_msg[MAX_LEN]; + char *pre_word, *next_word; + + char *token_str, *token_word; + + if ((msg = (char*)shmat(id_shm, NULL, 0)) == (char*)-1) { + perror("shmat"); + exit(1); + } + + quit = 0; + while (!quit) { + WAIT(id_sem, index); + if (strcmp(msg, "{{EOF}}") == 0) { + quit = 1; + } else { + switch (expr[0]) { + case '^': + action = 0; + break; + case '_': + action = 1; + break; + case '%': + action = 2; + break; + } + word = expr + 1; + + token = strtok_r(msg, " ", &token_str); + next_msg[0] = '\0'; + while (token) { + if (action == 0 || action == 1) { + j = strstr(token, word); + if (j) { + k[0] = '\0'; + for (w = 0; w < strlen(word); ++w) { + if (action == 0) + c[0] = toupper(word[w]); + else + c[0] = tolower(word[w]); + + strcat(k, c); + } + strncpy(j, k, strlen(word)); + } + } else { + strcpy(pre_word, word); + pre_word = strtok_r(pre_word, ",", &token_word); + next_word = strtok_r(NULL, ",", &token_word); + + j = strstr(token, pre_word); + if (j) { + strcpy(j, next_word); + } + } + strcat(next_msg, token); + strcat(next_msg, " "); + + token = strtok_r(NULL, " ", &token_str); + } + strcpy(msg, next_msg); + } + + SIGNAL(id_sem, 0); + if (index == n) + SIGNAL(id_sem, 0); + } +} + +int +main(int argc, char* argv[]) +{ + int id_shm; + int id_sem; + int i; + pid_t pid; + char buffer[MAX_LEN]; + char ch; + FILE* f; + char* msg; + + if (argc < 3) { + fprintf(stderr, "Usage: %s <file.txt> <filter-1> [filter-2] [...]", argv[0]); + exit(1); + } + + if ((f = fopen(argv[1], "r")) == NULL) { + perror("fopen"); + exit(1); + } + + if ((id_shm = shmget(IPC_PRIVATE, 1024, IPC_CREAT | IPC_EXCL | 0644)) == -1) { + perror("shmget"); + exit(1); + } + + if ((id_sem = semget(IPC_PRIVATE, argc - 1, IPC_CREAT | IPC_EXCL | 0644)) == -1) { + perror("semget"); + exit(1); + } + + semctl(id_sem, 0, SETVAL, 1); + + /* Create n process for n filters */ + for (i = 0; i < argc - 2; ++i) { + semctl(id_sem, i + 1, SETVAL, 0); + pid = fork(); + if (pid == -1) { + perror("fork"); + exit(1); + } + + if (pid == 0) { + filter(id_shm, id_sem, i + 1, argc - 2, argv[i + 2]); + exit(0); + } + } + + i = 0; + if ((msg = (char*)shmat(id_shm, NULL, 0)) == (char*)-1) { + perror("shmat"); + exit(1); + } + + while ((ch = fgetc(f)) != EOF) { + buffer[i++] = ch; + if (ch == '\n') { + buffer[i - 1] = '\0'; + WAIT(id_sem, 0); + strncpy(msg, buffer, strlen(buffer) + 1); + for (i = 0; i < argc - 2; ++i) { + SIGNAL(id_sem, i + 1); + WAIT(id_sem, 0); + } + printf("%s\n", msg); + i = 0; + } + } + + WAIT(id_sem, 0); + strcpy(msg, "{{EOF}}"); + for (i = 0; i < argc - 2; ++i) { + SIGNAL(id_sem, i + 1); + WAIT(id_sem, 0); + } + + for (i = 0; i < argc - 2; ++i) + wait(NULL); + + shmctl(id_shm, IPC_RMID, NULL); + semctl(id_sem, argc - 1, IPC_RMID); + + return 0; +} |