Initial commit

1 files changed, 94 insertions, 0 deletions

diff --git a/parallel_progs_by_args.c b/parallel_progs_by_args.c
new file mode 100644
index 0000000..97505ab
--- /dev/null
+++ b/parallel_progs_by_args.c
@@ -0,0 +1,94 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/wait.h>
+#include <string.h>
+
+struct item {
+    char *prog_name;
+    int pid;
+    struct item *next;
+};
+
+static int check_delimiter(char *arg)
+{
+    return !strncmp(arg, ";;", 3);
+}
+
+static void fill_in_item(char *arg, int pid, struct item **list)
+{
+    struct item *tmp_item = malloc(sizeof(struct item));
+    tmp_item->pid = pid;
+    tmp_item->prog_name = arg;
+    tmp_item->next = *list;
+    *list = tmp_item;
+}
+
+static void make_new_fork(char **begin_pos, struct item **list,
+                          int *process_counter)
+{
+    int pid = fork();
+    if(pid == -1) {
+        perror("fork error");
+        exit(1);
+    }
+    if(pid) {
+        fill_in_item(*begin_pos, pid, list);
+        ++*process_counter;
+    }
+    else {
+        execvp(*begin_pos, begin_pos);
+        perror(*begin_pos);
+        exit(1);
+    }
+}
+
+static char* find_name_by_pid(int pid, struct item *list)
+{
+    while(list) {
+        if(list->pid == pid)
+            return list->prog_name;
+        list = list->next;
+    }
+    return NULL;
+}
+
+static void clear_list(struct item *list)
+{
+    struct item *tmp;
+    while(list) {
+        tmp = list;
+        list = list->next;
+        free(tmp);
+    }
+}
+
+int main(int argc, char **argv)
+{
+    int status, pid, process_counter;
+    struct item *list = NULL;
+    process_counter = 0;
+    char **begin_pos, **end_pos;
+    if(argc == 1) {
+        fprintf(stderr, "too few arguments\n");
+        return 1;
+    }
+    ++argv;
+    for(begin_pos = argv, end_pos = begin_pos + 1; *end_pos != NULL; ) {
+        if(check_delimiter(*end_pos)) {
+            *end_pos = NULL;
+            make_new_fork(begin_pos, &list, &process_counter);
+            begin_pos = end_pos + 1;
+            end_pos = begin_pos + 1;
+        } else
+            ++end_pos;
+    }
+    make_new_fork(begin_pos, &list, &process_counter);
+    for( ; process_counter; --process_counter) {
+        pid = wait(&status);
+        if(WIFEXITED(status) && WEXITSTATUS(status) == 0)
+            printf("%s\n", find_name_by_pid(pid, list));
+    }
+    clear_list(list);
+    return 0;
+}