Userland: Port sysctl to use ArgsParser, and minor cleanups

Author: https://github.com/rburchell
Commit: 56aad835ad
Pull-request: https://github.com/SerenityOS/serenity/pull/50

Userland/sysctl.cpp

@@ -3,82 +3,12 @@
 #include <dirent.h>
 #include <errno.h>
 #include <string.h>
-#include <getopt.h>
 #include <fcntl.h>
+#include <AK/ArgsParser.h>
 #include <AK/AKString.h>
 #include <AK/StringBuilder.h>
 #include <AK/Vector.h>
 
-static bool flag_show_all = false;
-static int show_all();
-static int handle_var(const char*);
-
-static void usage()
-{
-    printf("usage: sysctl [-a] [variable[=value]]\n");
-}
-
-int main(int argc, char** argv)
-{
-    int opt;
-    while ((opt = getopt(argc, argv, "a")) != -1) {
-        switch (opt) {
-        case 'a':
-            flag_show_all = true;
-            break;
-        default:
-            usage();
-            return 0;
-        }
-    }
-
-    if (flag_show_all)
-        return show_all();
-
-    if (optind >= argc) {
-        usage();
-        return 0;
-    }
-
-    const char* var = argv[optind];
-
-    return handle_var(var);
-}
-
-int show_all()
-{
-    DIR* dirp = opendir("/proc/sys");
-    if (!dirp) {
-        perror("opendir");
-        return 1;
-    }
-    char pathbuf[PATH_MAX];
-
-    while (auto* de = readdir(dirp)) {
-        if (de->d_name[0] == '.')
-            continue;
-        sprintf(pathbuf, "/proc/sys/%s", de->d_name);
-        int fd = open(pathbuf, O_RDONLY);
-        if (fd < 0) {
-            perror("open");
-            continue;
-        }
-        char buffer[1024];
-        int nread = read(fd, buffer, sizeof(buffer));
-        close(fd);
-        if (nread < 0) {
-            perror("read");
-            continue;
-        }
-        buffer[nread] = '\0';
-        printf("%s = %s", de->d_name, buffer);
-        if (nread && buffer[nread - 1] != '\n')
-            printf("\n");
-    }
-    closedir(dirp);
-    return 0;
-}
-
 static String read_var(const String& name)
 {
     StringBuilder builder;
@@ -119,9 +49,44 @@ static void write_var(const String& name, const String& value)
     close(fd);
 }
 
-int handle_var(const char* var)
+
+static int handle_show_all()
 {
-    String spec(var, Chomp);
+    DIR* dirp = opendir("/proc/sys");
+    if (!dirp) {
+        perror("opendir");
+        return 1;
+    }
+    char pathbuf[PATH_MAX];
+
+    while (auto* de = readdir(dirp)) {
+        if (de->d_name[0] == '.')
+            continue;
+        sprintf(pathbuf, "/proc/sys/%s", de->d_name);
+        int fd = open(pathbuf, O_RDONLY);
+        if (fd < 0) {
+            perror("open");
+            continue;
+        }
+        char buffer[1024];
+        int nread = read(fd, buffer, sizeof(buffer));
+        close(fd);
+        if (nread < 0) {
+            perror("read");
+            continue;
+        }
+        buffer[nread] = '\0';
+        printf("%s = %s", de->d_name, buffer);
+        if (nread && buffer[nread - 1] != '\n')
+            printf("\n");
+    }
+    closedir(dirp);
+    return 0;
+}
+
+static int handle_var(const String& var)
+{
+    String spec(var.characters(), Chomp);
     auto parts = spec.split('=');
     String variable_name = parts[0];
     bool is_write = parts.size() > 1;
@@ -136,3 +101,24 @@ int handle_var(const char* var)
     printf(" -> %s\n", read_var(variable_name).characters());
     return 0;
 }
+
+int main(int argc, char** argv)
+{
+    AK::ArgsParser args_parser("sysctl");
+
+    args_parser.add_arg("a", "show all variables");
+    args_parser.set_single_value("variable=[value]");
+
+    AK::ArgsParserResult args = args_parser.parse(argc, (const char**)argv);
+
+    if (args.is_present("a")) {
+        return handle_show_all();
+    } else if (args.get_single_values().size() != 1) {
+        args_parser.print_usage();
+        return 0;
+    }
+
+    Vector<String> values = args.get_single_values();
+    return handle_var(values[0]);
+}
+