init commit

3sem/kr/002.c

@@ -0,0 +1,41 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <signal.h>
+#include <fcntl.h>
+
+volatile int counter = 0;
+volatile int signals = 0;
+
+int fd2;
+
+void handler(int sig) {
+    ++signals;
+    if (signals < 3) {
+        printf("%d\n", counter / 2);
+    } else {
+        lseek(fd2, 0, SEEK_SET);
+        char buf;
+        while (read(fd2, &buf, 1) > 0) {
+            write(1, &buf, 1);
+        }
+        exit(0);
+    }
+
+}
+
+int main(int argc, char** argv) {
+    signal(SIGINT, handler);
+
+    int fd1 = open(argv[1], O_RDONLY, 0666);
+    fd2 = open(argv[2], O_CREAT | O_WRONLY);
+
+    char buf;
+    while (read(fd1, &buf, 1) > 0) {
+        if (counter % 2 == 0) {
+            write(fd2, &buf, 1);
+        }
+        ++counter;
+    }
+
+    return 0;
+}