[SP/P03] Solved exercises

7 files changed, 114 insertions, 0 deletions

diff --git a/Year 3/System programming/Practice03/ex1.c b/Year 3/System programming/Practice03/ex1.c
new file mode 100644
index 0000000..944ee0a
--- /dev/null
+++ b/Year 3/System programming/Practice03/ex1.c
@@ -0,0 +1,25 @@
+#include <fcntl.h> // open
+#include <unistd.h> // close
+#include <stdio.h> // perror
+#include <sys/stat.h> // mode_t
+
+int main(int argc, char* argv[]) {
+	int f1 = open(argv[1], O_CREAT, 0777);
+	if (f1 < 0) {
+		perror("open");
+		return 1;
+	}
+
+	mode_t oldmask = umask(0);
+
+	int f2 = open(argv[2], O_CREAT, 0777);
+	if (f2 < 0) {
+		perror("open");
+		return 2;
+	}
+
+	umask(oldmask);
+
+	close(f1);
+	close(f2);
+}
diff --git a/Year 3/System programming/Practice03/ex2.c b/Year 3/System programming/Practice03/ex2.c
new file mode 100644
index 0000000..4b67c11
--- /dev/null
+++ b/Year 3/System programming/Practice03/ex2.c
@@ -0,0 +1,16 @@
+#include <sys/stat.h>
+#include <stdio.h> // perror
+
+int main(int argc, char* argv[]) {
+	for (int i = 1; i < argc; i++) {
+		struct stat buf;
+		if(stat(argv[i], &buf) < 0) {
+			perror("stat");
+			return 1;
+		}
+		if (chmod(argv[i], (buf.st_mode | S_IWGRP) & ~S_IXOTH) < 0) {
+			perror("chmod");
+			return 2;
+		}
+	}
+}
diff --git a/Year 3/System programming/Practice03/ex3.c b/Year 3/System programming/Practice03/ex3.c
new file mode 100644
index 0000000..45019bd
--- /dev/null
+++ b/Year 3/System programming/Practice03/ex3.c
@@ -0,0 +1,17 @@
+#include <sys/stat.h>
+#include <utime.h> // struct utimbuf, utime
+#include <stdio.h> // perror
+
+int main(int argc, char* argv[]) {
+	struct stat buf;
+	if(stat(argv[1], &buf) < 0) {
+		perror("stat");
+		return 1;
+	}
+
+	struct utimbuf newtime = { buf.st_atime - 60 * 60 * 1, buf.st_mtime + 60 * 1 };
+	if (utime(argv[1], &newtime) < 0) {
+		perror("utime");
+		return 2;
+	}
+}
diff --git a/Year 3/System programming/Practice03/ex4.c b/Year 3/System programming/Practice03/ex4.c
new file mode 100644
index 0000000..0358e6c
--- /dev/null
+++ b/Year 3/System programming/Practice03/ex4.c
@@ -0,0 +1,13 @@
+#include <unistd.h> // link, unlink
+#include <stdio.h> // perror
+
+int main(int argc, char* argv[]) {
+	if(link(argv[1], argv[2]) < 0) {
+		perror("link");
+		return 1;
+	}
+	if(unlink(argv[1]) < 0) {
+		perror("unlink");
+		return 2;
+	}
+}
diff --git a/Year 3/System programming/Practice03/ex5.c b/Year 3/System programming/Practice03/ex5.c
new file mode 100644
index 0000000..22e6991
--- /dev/null
+++ b/Year 3/System programming/Practice03/ex5.c
@@ -0,0 +1,16 @@
+#include <unistd.h> // symlink, readlink
+#include <stdio.h> // perror, printf
+
+int main(int argc, char* argv[]) {
+	if(symlink(argv[1], argv[2]) < 0) {
+		perror("symlink");
+		return 1;
+	}
+
+	char buf[1024];
+	if(readlink(argv[2], buf, 1024) < 0) {
+		perror("readlink");
+		return 2;
+	}
+	printf("%s\n", buf);
+}
diff --git a/Year 3/System programming/Practice03/ex6.c b/Year 3/System programming/Practice03/ex6.c
new file mode 100644
index 0000000..d327085
--- /dev/null
+++ b/Year 3/System programming/Practice03/ex6.c
@@ -0,0 +1,18 @@
+#include <stdio.h> // perror
+#include <sys/stat.h> // mkdir
+#include <unistd.h> // symlink, rmdir
+
+int main(int argc, char* argv[]) {
+	if(mkdir("./test", 0777) < 0) {
+		perror("mkdir");
+		return 1;
+	}
+	if(symlink("./test/myfile.txt", "./test/link.txt") < 0) {
+		perror("symlink");
+		return 2;
+	}
+	if(rmdir("./test") < 0) {
+		perror("rmdir");
+		return 3;
+	}
+}
diff --git a/Year 3/System programming/Practice03/ex7-cd.c b/Year 3/System programming/Practice03/ex7-cd.c
new file mode 100644
index 0000000..ad3b7ec
--- /dev/null
+++ b/Year 3/System programming/Practice03/ex7-cd.c
@@ -0,0 +1,9 @@
+#include <unistd.h> // chdir
+#include <stdio.h> // perror
+
+int main(int argc, char* argv[]) {
+	if(chdir(argv[1]) < 0) {
+		perror("chdir");
+		return 1;
+	}
+}