From 0b28848f9b6584a44054f4e46871b1878ada44b8 Mon Sep 17 00:00:00 2001
From: Santo Cariotti <santo@dcariotti.me>
Date: Mon, 5 Jul 2021 17:23:29 +0200
Subject: os: add homework 1

---
 Year_2/OS/hw/hw1.c | 90 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 90 insertions(+)
 create mode 100644 Year_2/OS/hw/hw1.c

(limited to 'Year_2/OS')

diff --git a/Year_2/OS/hw/hw1.c b/Year_2/OS/hw/hw1.c
new file mode 100644
index 0000000..814b840
--- /dev/null
+++ b/Year_2/OS/hw/hw1.c
@@ -0,0 +1,90 @@
+/*
+    Homework n.1
+
+    Scrivere un programma in linguaggio C che permetta di copiare un numero
+    arbitrario di file regolari su una directory di destinazione preesistente.
+
+    Il programma dovra' accettare una sintassi del tipo:
+     $ homework-1 file1.txt path/file2.txt "nome con spazi.pdf" directory-destinazione
+*/
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+int copyfile(int*, int*);
+
+int main(int argc, char* argv[0])
+{
+    int fd, fd_dst;
+    int i;
+    unsigned long size;
+    char dst[1024];
+    char buffer[1024];
+    char *p1, *p2;
+
+    if (argc < 3) {
+        fprintf(stderr, "Use %s <src1> [<src2>..] <dst>", argv[0]);
+        exit(1);
+    }
+
+    i = 1;
+    strncpy(dst, argv[argc - 1], 1024);
+    size = strlen(dst);
+    strncpy(dst + size, "/", 1024 - size);
+    size++;
+    while (i < argc - 1) {
+        /* Open the source file */
+        if ((fd = open(argv[i], O_RDONLY)) == -1) {
+            perror(argv[i]);
+            exit(1);
+        }
+
+        /* Open the destination file */
+        strncpy(buffer, dst, size);
+        p1 = p2 = argv[i++];
+        while (*p2 != '\0') {
+            if (*p2 == '/')
+                p1 = p2 + 1;
+            p2++;
+        }
+        strncpy(buffer + size, p1, 1024 - size);
+
+        if ((fd_dst = open(buffer, O_CREAT | O_TRUNC | O_WRONLY, 0644)) == -1) {
+            perror(argv[argc - 1]);
+            exit(1);
+        }
+
+        /* Ignore the return value, the last number of bytes returned. Result is
+         * always = 0 */
+        copyfile(&fd, &fd_dst);
+        close(fd);
+        close(fd_dst);
+        printf("`%s` written successfully\n", buffer);
+    }
+
+    return 0;
+}
+
+int copyfile(int* src, int* dst)
+{
+    int n;
+    char* buffer[1024];
+
+    do {
+        if ((n = read(*src, buffer, 1024)) == -1) {
+            perror("Error reading the source file");
+            exit(1);
+        }
+
+        if (write(*dst, buffer, n) == -1) {
+            perror("Error writing the destination file");
+            exit(1);
+        }
+    } while (n > 0);
+
+    return n;
+}
-- 
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