Added more exercises

RisingFisan · May 10, 2020 · 34b3a7a · 34b3a7a
1 parent 6eb527c
commit 34b3a7a
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Showing 7 changed files with 306 additions and 9 deletions.
diff --git a/Guião 1/mycp/main.c b/Guião 1/mycp/main.c
@@ -23,7 +23,7 @@ int main(int argc, char const *argv[]) {
     int source = open(argv[1], O_RDONLY);
     if(source == -1) {
         printf("ERROR - %s - No such file or directory\n", argv[1]);
-        return 1;
+        exit(1);
     }
 
     int dest = open(argv[2], O_WRONLY | O_CREAT | O_TRUNC, 0644);

diff --git a/Guião 3/Ex4.c b/Guião 3/Ex4.c
@@ -5,17 +5,14 @@
 
 int main(void) {
 	char buffer[1024];
-	puts("Number of elements:");
-	fgets(buffer, 1024, stdin);
-	long N = strtod(buffer, NULL);
-	char* args[N+2];
+	char* args[1024];
 	args[0] = "./Ex3";
-	for(size_t i = 1; i <= N; i++) {
-		fgets(buffer, 1024, stdin);
+	size_t i = 1;
+	while(fgets(buffer, 1024, stdin)) {
 		buffer[strcspn(buffer, "\n\r")] = 0;
-		args[i] = strdup(buffer);
+		args[i++] = strdup(buffer);
 	}
-	args[N+1] = NULL;
+	args[i] = NULL;
 	execv("./Ex3", args);
 	return 0;
 }
diff --git a/Guião 3/Ex7.c b/Guião 3/Ex7.c
@@ -0,0 +1,53 @@
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/wait.h>
+
+ssize_t readline(int fd, char* buf, int size);
+
+int main(int argc, char const *argv[]) {
+    char* buffer = calloc(1024, sizeof(char));
+    char* args[1024];
+    size_t len = 0;
+    size_t back_n = 0;
+    while((len = readline(STDIN_FILENO, buffer, 1024)) > 0) {
+        size_t i = 0;
+        char* token;
+        while((token = strtok_r(buffer, " ", &buffer))) {
+            args[i++] = strdup(token);
+        }
+        int background = 0;
+        if(strcmp(args[0], "exit") == 0) {
+            break;
+        }
+        if(strcmp(args[i-1], "&") == 0) {
+            background = 1;
+            i--;
+        }
+        args[i] = NULL;
+
+        int pid;
+        if(!(pid = fork())) {
+            execvp(args[0], args);
+        }
+        else {
+            if(!background) waitpid(pid, NULL, 0);
+            else back_n++;
+        }
+    }
+    for(size_t i = 0; i < back_n; i++) wait(NULL);
+    return 0;
+}
+
+ssize_t readline(int fd, char* buf, int size) {
+    ssize_t bytesRead = read(fd, buf, size);
+    if(!bytesRead) return 0;
+
+    size_t len = strcspn(buf,"\n");
+    if(bytesRead < len) len = bytesRead;
+    buf[len] = 0;
+
+    lseek(fd, len - bytesRead, SEEK_CUR);
+    return len;
+}
diff --git a/Guião 4/Ex4.c b/Guião 4/Ex4.c
@@ -0,0 +1,34 @@
+#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/wait.h>
+#include <stdlib.h>
+
+int main(int argc, char const *argv[]) {
+    if(argc < 6) exit(1);
+
+    int input_fd;
+    int output_fd;
+
+    if(strcmp(argv[1], "-i") == 0) {
+        input_fd = open(argv[2], O_RDONLY);
+    } else exit(1);
+
+    if(strcmp(argv[3], "-o") == 0) {
+        output_fd = open(argv[4], O_WRONLY | O_CREAT | O_TRUNC, 0644);
+    } else exit(1);
+
+    dup2(input_fd, STDIN_FILENO);
+    dup2(output_fd, STDOUT_FILENO);
+
+    close(input_fd);
+    close(output_fd);
+
+    argv[argc] = NULL;
+
+    if(fork() == 0) {
+        execvp(argv[5], argv + 5);
+        _exit(1);
+    } else wait(NULL);
+    return 0;
+}
diff --git a/Guião 4/Ex5.c b/Guião 4/Ex5.c
@@ -0,0 +1,103 @@
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/wait.h>
+
+ssize_t readline(int fd, char* buf, int size);
+
+int main(int argc, char const *argv[]) {
+    char* buffer = calloc(1024, sizeof(char));
+    char* args[1024];
+    size_t len = 0;
+    size_t back_n = 0;
+
+    int stdin_backup = dup(STDIN_FILENO);
+    int stdout_backup = dup(STDOUT_FILENO);
+    int stderr_backup = dup(STDERR_FILENO);
+
+    while((len = readline(STDIN_FILENO, buffer, 1024)) > 0) {
+        size_t i = 0;
+        char* token;
+        while((token = strtok_r(buffer, " ", &buffer))) {
+            args[i] = strdup(token);
+            if(i > 1) {
+                if(strcmp(args[i-1],">") == 0) {
+                    int fd = open(args[i], O_WRONLY | O_CREAT | O_TRUNC, 0644);
+                    dup2(fd, STDOUT_FILENO);
+                    close(fd);
+                    i-=2;
+                }
+                else if(strcmp(args[i-1],">>") == 0) {
+                    int fd = open(args[i], O_WRONLY | O_CREAT | O_APPEND, 0644);
+                    dup2(fd, STDOUT_FILENO);
+                    close(fd);
+                    i-=2;
+                }
+                else if(strcmp(args[i-1],"<") == 0) {
+                    int fd = open(args[i], O_RDONLY);
+                    dup2(fd, STDIN_FILENO);
+                    close(fd);
+                    i-=2;
+                }
+                else if(strcmp(args[i-1],"2>") == 0) {
+                    int fd = open(args[i], O_WRONLY | O_CREAT | O_TRUNC, 0644);
+                    dup2(fd, STDERR_FILENO);
+                    close(fd);
+                    i-=2;
+                }
+                else if(strcmp(args[i-1],"2>>") == 0) {
+                    int fd = open(args[i], O_WRONLY | O_CREAT | O_APPEND, 0644);
+                    dup2(fd, STDERR_FILENO);
+                    close(fd);
+                    i-=2;
+                }
+            }
+            i++;
+        }
+        int background = 0;
+        if(strcmp(args[0], "exit") == 0) {
+            break;
+        }
+        if(strcmp(args[i-1], "&") == 0) {
+            background = 1;
+            i--;
+        }
+        args[i] = NULL;
+
+        int pid;
+        if(!(pid = fork())) {
+            execvp(args[0], args);
+            _exit(1);
+        }
+        else {
+            if(!background) waitpid(pid, NULL, 0);
+            else back_n++;
+        }
+
+        dup2(stdin_backup, STDIN_FILENO);
+        dup2(stdout_backup, STDOUT_FILENO);
+        dup2(stderr_backup, STDERR_FILENO);
+    }
+
+    for(size_t i = 0; i < back_n; i++) wait(NULL);
+
+    close(stdin_backup);
+    close(stdout_backup);
+    close(stderr_backup);
+
+    return 0;
+}
+
+ssize_t readline(int fd, char* buf, int size) {
+    ssize_t bytesRead = read(fd, buf, size);
+    if(!bytesRead) return 0;
+
+    size_t len = strcspn(buf,"\n");
+    if(bytesRead < len) len = bytesRead;
+    buf[len] = 0;
+
+    lseek(fd, len - bytesRead, SEEK_CUR);
+    return len;
+}
diff --git a/Guião 5/Ex4.c b/Guião 5/Ex4.c
@@ -0,0 +1,34 @@
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/wait.h>
+
+int main(int argc, char const *argv[]) {
+    int pipe_fd[2];
+    if(pipe(pipe_fd) < 0) {
+        perror("pipe");
+        exit(1);
+    }
+
+    if(fork() == 0) {
+        close(pipe_fd[0]);
+        dup2(pipe_fd[1], STDOUT_FILENO);
+        close(pipe_fd[1]);
+        execlp("ls", "ls", "/etc", NULL);
+        _exit(1);
+    }
+    else if (fork() == 0) {
+        close(pipe_fd[1]);
+        dup2(pipe_fd[0], STDIN_FILENO);
+        close(pipe_fd[0]);
+        execlp("wc", "wc", "-l", NULL);
+        _exit(1);
+    }
+    else {
+        close(pipe_fd[0]);
+        close(pipe_fd[1]);
+        if (wait(NULL) == -1) puts("Error");
+        if (wait(NULL) == -1) puts("Error");
+    }
+    return 0;
+}
diff --git a/Guião 5/Ex5.c b/Guião 5/Ex5.c
@@ -0,0 +1,76 @@
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/wait.h>
+
+int main(int argc, char const *argv[]) {
+    int pipe_fd[2][2];
+    if(pipe(pipe_fd[0]) < 0) {
+        perror("pipe");
+        exit(1);
+    }
+
+    if(fork() == 0) {
+        close(pipe_fd[0][0]);
+        dup2(pipe_fd[0][1], STDOUT_FILENO);
+        close(pipe_fd[0][1]);
+        execlp("grep", "grep", "-v", "^#", "/etc/passwd", NULL);
+        _exit(1);
+    }
+
+    close(pipe_fd[0][1]);
+
+    if(pipe(pipe_fd[1]) < 0) {
+        perror("pipe");
+        exit(1);
+    }
+
+    if (fork() == 0) {
+        close(pipe_fd[1][0]);
+
+        dup2(pipe_fd[0][0], STDIN_FILENO);
+        close(pipe_fd[0][0]);
+        dup2(pipe_fd[1][1], STDOUT_FILENO);
+        close(pipe_fd[1][1]);
+        execlp("cut", "cut", "-f7", "-d:", NULL);
+        _exit(1);
+    }
+
+    close(pipe_fd[0][0]);
+    close(pipe_fd[1][1]);
+
+    if(pipe(pipe_fd[2]) < 0) {
+        perror("pipe");
+        exit(1);
+    }
+
+    if (fork() == 0) {
+        close(pipe_fd[2][0]);
+
+        dup2(pipe_fd[1][0], STDIN_FILENO);
+        close(pipe_fd[1][0]);
+        dup2(pipe_fd[2][1], STDOUT_FILENO);
+        close(pipe_fd[2][1]);
+        execlp("uniq", "uniq", NULL);
+        _exit(1);
+    }
+
+    close(pipe_fd[1][0]);
+    close(pipe_fd[2][1]);
+
+    if (fork() == 0) {
+        dup2(pipe_fd[2][0], STDIN_FILENO);
+        close(pipe_fd[2][0]);
+        execlp("wc", "wc", "-l", NULL);
+        _exit(1);
+    }
+
+    close(pipe_fd[2][0]);
+
+    if (wait(NULL) == -1) puts("Error");
+    if (wait(NULL) == -1) puts("Error");
+    if (wait(NULL) == -1) puts("Error");
+    if (wait(NULL) == -1) puts("Error");
+
+    return 0;
+}