Add README

.gitignore

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-# Ignore build directory
 build/
 
-# Ignore CMake generated files
 CMakeCache.txt
 CMakeFiles/
 cmake_install.cmake

CMakeLists.txt

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+cmake_minimum_required(VERSION 3.10)
+project(ConsoleUtility C)
+set(CMAKE_C_STANDARD 99)
+add_executable(console_utility src/main.c src/users.c src/processes.c src/logging.c src/error_handling.c)

README.md

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+# Console Utility
+
+## Build Process
+```sh
+mkdir build
+cd build
+cmake ..
+make
+```
+
+## Usage Examples
+- Display users and home directories:
+  ```sh
+  ./console_utility -u
+  ```
+- Display running processes:
+  ```sh
+  ./console_utility -p
+  ```
+- Redirect output to a log file:
+  ```sh
+  ./console_utility -u -l output.log
+  ```
+- Redirect errors to a file:
+  ```sh
+  ./console_utility -p -e errors.log
+  ```
+- Show help:
+  ```sh
+  ./console_utility -h
+  ```

src/error_handling.c

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+#include "error_handling.h"
+#include <stdio.h>
+
+FILE *open_error_file(const char *path) {
+    FILE *file = fopen(path, "w");
+    if (!file) {
+        fprintf(stderr, "Error: Cannot open error file %s\n", path);
+        return NULL;
+    }
+    return file;
+}

src/error_handling.h

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+#ifndef ERROR_HANDLING_H
+#define ERROR_HANDLING_H
+#include <stdio.h>
+FILE *open_error_file(const char *path);
+#endif

src/logging.c

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+#include "logging.h"
+#include <stdio.h>
+
+FILE *open_log_file(const char *path) {
+    FILE *file = fopen(path, "w");
+    if (!file) {
+        fprintf(stderr, "Error: Cannot open log file %s\n", path);
+        return NULL;
+    }
+    return file;
+}

src/logging.h

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+#ifndef LOGGING_H
+#define LOGGING_H
+#include <stdio.h>
+FILE *open_log_file(const char *path);
+#endif

src/main.c

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+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <string.h>
+#include "users.h"
+#include "processes.h"
+#include "logging.h"
+#include "error_handling.h"
+
+void setup_error_redirection(char *error_file, FILE **err_fp) {
+    if (error_file) {
+        FILE *temp_err_fp = fopen(error_file, "w");
+        if (!temp_err_fp) {
+            perror("Failed to open error log file");
+            exit(1);
+        }
+        fflush(stderr); // Ensure all previous stderr output is flushed
+        if (dup2(fileno(temp_err_fp), STDERR_FILENO) == -1) {
+            perror("Failed to redirect stderr to file");
+            fclose(temp_err_fp);
+            exit(1);
+        }
+        *err_fp = temp_err_fp;
+    }
+}
+
+void setup_log_redirection(char *log_file, FILE **log_fp) {
+    if (log_file) {
+        FILE *temp_log_fp = fopen(log_file, "w");
+        if (!temp_log_fp) {
+            perror("Failed to open log file");
+            exit(1);
+        }
+        fflush(stdout);
+        if (dup2(fileno(temp_log_fp), STDOUT_FILENO) == -1) {
+            perror("Failed to redirect stdout to file");
+            fclose(temp_log_fp);
+            exit(1);
+        }
+        *log_fp = temp_log_fp;
+    }
+}
+
+int main(int argc, char *argv[]) {
+    int opt;
+    char *log_file = NULL;
+    char *error_file = NULL;
+    int show_users = 0, show_processes = 0;
+    FILE *log_fp = stdout, *err_fp = stderr;
+
+    // Early error redirection handling to ensure stderr is set up before parsing arguments
+    for (int i = 1; i < argc; i++) {
+        if ((strcmp(argv[i], "-e") == 0 || strcmp(argv[i], "--errors") == 0) && i + 1 < argc) {
+            error_file = argv[i + 1];
+            setup_error_redirection(error_file, &err_fp);
+        }
+    }
+
+    struct option long_options[] = {
+        {"users", no_argument, 0, 'u'},
+        {"processes", no_argument, 0, 'p'},
+        {"log", required_argument, 0, 'l'},
+        {"errors", required_argument, 0, 'e'},
+        {"help", no_argument, 0, 'h'},
+        {0, 0, 0, 0}
+    };
+
+    while ((opt = getopt_long(argc, argv, "upl:e:h", long_options, NULL)) != -1) {
+        switch (opt) {
+            case 'u': show_users = 1; break;
+            case 'p': show_processes = 1; break;
+            case 'l': log_file = optarg; break;
+            case 'e': error_file = optarg; break;
+            case 'h':
+                printf("Usage: %s [options]\n", argv[0]);
+                printf("  -u, --users       List users and home directories\n");
+                printf("  -p, --processes   List running processes\n");
+                printf("  -l, --log PATH    Redirect output to a file\n");
+                printf("  -e, --errors PATH Redirect errors to a file\n");
+                printf("  -h, --help        Show this help message\n");
+                return 0;
+            default:
+                fprintf(stderr, "Unknown option. Use -h for help.\n");
+                return 1;
+        }
+    }
+
+    // Ensure log redirection is handled after argument parsing
+    setup_log_redirection(log_file, &log_fp);
+
+    if (show_users) {
+        list_users(log_fp);
+    }
+    if (show_processes) {
+        list_processes(log_fp);
+    }
+
+    if (log_fp != stdout) fclose(log_fp);
+    if (err_fp != stderr) fclose(err_fp);
+
+    return 0;
+}

src/processes.c

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+#include "processes.h"
+#include <stdio.h>
+#include <stdlib.h>
+
+void list_processes(FILE *output) {
+    FILE *fp = popen("ps -eo pid,comm --sort=pid", "r");
+    if (fp == NULL) {
+        fprintf(output, "Error opening process list\n");
+        return;
+    }
+    char line[256];
+    while (fgets(line, sizeof(line), fp) != NULL) {
+        fprintf(output, "%s", line);
+    }
+    pclose(fp);
+}

src/processes.h

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+#ifndef PROCESSES_H
+#define PROCESSES_H
+#include <stdio.h>
+void list_processes(FILE *output);
+#endif

src/users.c

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+#include "users.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <pwd.h>
+
+void list_users(FILE *output) {
+    struct passwd *pw;
+    while ((pw = getpwent()) != NULL) {
+        fprintf(output, "%s: %s\n", pw->pw_name, pw->pw_dir);
+    }
+    endpwent();
+}

src/users.h

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+#ifndef USERS_H
+#define USERS_H
+#include <stdio.h>
+void list_users(FILE *output);
+#endif