mfshell: add configuration file parsing

mfshell/main.c

@@ -24,6 +24,8 @@
 #include <stdlib.h>
 #include <string.h>
 #include <wordexp.h>
+#include <pwd.h>
+#include <unistd.h>
 
 #include "../utils/strings.h"
 #include "mfshell.h"
@@ -32,6 +34,16 @@ static void     mfshell_run(mfshell * shell);
 
 static void     mfshell_parse_commands(mfshell * shell, char *command);
 
+struct mfshell_user_options {
+    char *username;
+    char *password;
+    char *command;
+    char *server;
+    char *config;
+} mfshell_user_options = {
+    NULL, NULL, NULL, NULL, NULL
+};
+
 void print_help(const char *cmd)
 {
     fprintf(stderr, "A shell to access a MediaFire account.\n");
@@ -59,22 +71,39 @@ void print_help(const char *cmd)
     fprintf(stderr, "\n");
     fprintf(stderr, "     %s -c help\n", cmd);
     fprintf(stderr, "\n");
+    fprintf(stderr,
+            "If arguments are given multiple times, the first one will be\n"
+            "used.\n");
+    fprintf(stderr, "\n");
+    fprintf(stderr,
+            "Arguments given on the commandline will overwrite arguments\n"
+            "given in the configuration file\n");
+    fprintf(stderr, "\n");
+    fprintf(stderr,
+            "The configuration file is parsed as if it was an argument\n"
+            "string except that linebreaks are allowed between arguments.\n"
+            "Lines starting with a # (hash) are ignored\n");
 }
 
 void
-parse_argv(int argc, char *const argv[], char **username,
+parse_argv(int argc, char *const argv[])
-           char **password, char **server, char **command)
 {
     static struct option long_options[] = {
         {"command", required_argument, 0, 'c'},
+        {"config", required_argument, 0, 'f'},
         {"username", required_argument, 0, 'u'},
         {"password", required_argument, 0, 'p'},
         {"server", required_argument, 0, 's'},
         {"help", no_argument, 0, 'h'},
-        {"version", no_argument, 0, 'v'}
+        {"version", no_argument, 0, 'v'},
+        {0, 0, 0, 0}
     };
     int             c;
 
+    // resetting optind because we want to be able to call getopt_long
+    // multiple times for the commandline arguments as well as for the
+    // configuration file
+    optind = 0;
     for (;;) {
         c = getopt_long(argc, argv, "c:u:p:s:hv", long_options, NULL);
         if (c == -1)
@@ -82,17 +111,24 @@ parse_argv(int argc, char *const argv[], char **username,
 
         switch (c) {
             case 'c':
-                *command = strdup(optarg);
+                if (mfshell_user_options.command == NULL)
+                    mfshell_user_options.command = strdup(optarg);
                 break;
             case 'u':
-                *username = strdup(optarg);
+                if (mfshell_user_options.username == NULL)
+                    mfshell_user_options.username = strdup(optarg);
                 break;
             case 'p':
-                *password = strdup(optarg);
+                if (mfshell_user_options.password == NULL)
+                    mfshell_user_options.password = strdup(optarg);
                 break;
             case 's':
-                *server = strdup(optarg);
+                if (mfshell_user_options.server == NULL)
+                    mfshell_user_options.server = strdup(optarg);
                 break;
+            case 'f':
+                if (mfshell_user_options.config == NULL)
+                    mfshell_user_options.config = strdup(optarg);
             case 'h':
                 print_help(argv[0]);
                 exit(0);
@@ -112,56 +148,158 @@ parse_argv(int argc, char *const argv[], char **username,
         exit(1);
     }
 
-    if (*password != NULL && *username == NULL) {
+    if (mfshell_user_options.password != NULL &&
+        mfshell_user_options.username == NULL) {
         fprintf(stderr, "You cannot pass the password without the username\n");
         exit(1);
     }
 }
 
+static void parse_config_file(FILE *fp)
+{
+    // read the config file line by line and pass each line to wordexp to
+    // retain proper quoting
+    char *line = NULL;
+    size_t len = 0;
+    ssize_t read;
+    wordexp_t p;
+    int ret, i;
+    int argc;
+    char **argv;
+
+    while ((read = getline(&line, &len, fp)) != -1) {
+        if (line[0] == '#')
+            continue;
+
+        // replace possible trailing newline by zero
+        if (line[strlen(line) - 1] == '\n')
+            line[strlen(line) - 1] = '\0';
+        ret = wordexp(line, &p, WRDE_SHOWERR | WRDE_UNDEF);
+        if (ret != 0) {
+            switch (ret) {
+                case WRDE_BADCHAR:
+                    fprintf(stderr, "wordexp: WRDE_BADCHAR\n");
+                    break;
+                case WRDE_BADVAL:
+                    fprintf(stderr, "wordexp: WRDE_BADVAL\n");
+                    break;
+                case WRDE_CMDSUB:
+                    fprintf(stderr, "wordexp: WRDE_CMDSUB\n");
+                    break;
+                case WRDE_NOSPACE:
+                    fprintf(stderr, "wordexp: WRDE_NOSPACE\n");
+                    break;
+                case WRDE_SYNTAX:
+                    fprintf(stderr, "wordexp: WRDE_SYNTAX\n");
+                    break;
+            }
+            wordfree(&p);
+            continue;
+        }
+        // prepend a dummy program name so that getopt_long will be able to
+        // parse it
+        argc = p.we_wordc + 1;
+        // allocate one more than argc for trailing NULL
+        argv = (char **)malloc(sizeof(char*)*(argc+1));
+        argv[0] = ""; // dummy program name
+        for (i = 1; i < argc; i++)
+            argv[i] = p.we_wordv[i-1];
+        argv[argc] = NULL;
+        parse_argv(argc, argv);
+        free(argv);
+        wordfree(&p);
+    }
+    free(line);
+}
+
+static void parse_config()
+{
+    FILE *fp;
+    char *homedir;
+    // parse the configuration file
+    // if a value is not set (it is NULL) then it has not been set by the
+    // commandline and should be set by the configuration file
+
+    // try set config file first if set
+    if (mfshell_user_options.config != NULL &&
+        (fp = fopen(mfshell_user_options.config, "r")) != NULL) {
+        parse_config_file(fp);
+        fclose(fp);
+        return;
+    }
+
+    // try "./.mediafire-tools.conf" second
+    if ((fp = fopen("./.mediafire-tools.conf", "r")) != NULL) {
+        parse_config_file(fp);
+        fclose(fp);
+        return;
+    }
+
+    // try "~/.mediafire-tools.conf" third
+    if ((homedir = getenv("HOME")) == NULL) {
+        homedir = getpwuid(getuid())->pw_dir;
+    }
+    homedir = strdup_printf("%s/.mediafire-tools.conf", homedir);
+    if ((fp = fopen("./.mediafire-tools.conf", "r")) != NULL) {
+        parse_config_file(fp);
+        fclose(fp);
+    }
+    free(homedir);
+}
+
 int main(int argc, char *const argv[])
 {
     mfshell        *shell;
-    char           *server = "www.mediafire.com";
-    char           *username = NULL;
-    char           *password = NULL;
-    char           *command = NULL;
     char           *auth_cmd;
 
     SSL_library_init();
 
-    parse_argv(argc, argv, &username, &password, &server, &command);
+    parse_argv(argc, argv);
+
+    parse_config();
+
+    // if server was neither set on the commandline nor in the config, set it
+    // to the default value
+    if (mfshell_user_options.server == NULL) {
+        mfshell_user_options.server = strdup("www.mediafire.com");
+    }
 
     shell = mfshell_create(35860, "2c6dq0gb2sr8rgsue5a347lzpjnaay46yjazjcjg",
-                           server);
+                           mfshell_user_options.server);
 
-    if (username != NULL) {
+    // if at least username was set, authenticate automatically
-        if (password != NULL) {
+    if (mfshell_user_options.username != NULL) {
-            auth_cmd = strdup_printf("auth %s %s", username, password);
+        if (mfshell_user_options.password != NULL) {
+            auth_cmd = strdup_printf("auth %s %s",
+                                     mfshell_user_options.username,
+                                     mfshell_user_options.password);
         } else {
-            auth_cmd = strdup_printf("auth %s", username);
+            auth_cmd = strdup_printf("auth %s", mfshell_user_options.username);
         }
         mfshell_parse_commands(shell, auth_cmd);
         free(auth_cmd);
     }
 
-    if (command == NULL) {
+    if (mfshell_user_options.command == NULL) {
         // begin shell mode
         mfshell_run(shell);
     } else {
         // interpret command
-        mfshell_parse_commands(shell, command);
+        mfshell_parse_commands(shell, mfshell_user_options.command);
     }
 
     mfshell_destroy(shell);
 
-    if (server != NULL && strcmp("www.mediafire.com", server) != 0)
+    if (mfshell_user_options.server != NULL)
-        free(server);
+        free(mfshell_user_options.server);
-    if (username != NULL)
+    if (mfshell_user_options.username != NULL)
-        free(username);
+        free(mfshell_user_options.username);
-    if (password != NULL)
+    if (mfshell_user_options.password != NULL)
-        free(password);
+        free(mfshell_user_options.password);
-    if (command != NULL)
+    if (mfshell_user_options.command != NULL)
-        free(command);
+        free(mfshell_user_options.command);
+    if (mfshell_user_options.config != NULL)
+        free(mfshell_user_options.config);
 
     return 0;
 }

tests/valgrind.sh

@@ -17,4 +17,8 @@ esac
 
 cmd="valgrind --suppressions="${source_dir}/valgrind.supp" --fullpath-after="$source_dir" --tool=memcheck --leak-check=yes --show-reachable=yes --num-callers=20 --track-fds=yes --track-origins=yes"
 
-$cmd "${binary_dir}/mediafire-shell" -c "help; whoami"
+if [ ! -f "./.mediafire-tools.conf" -a ! -f "~/.mediafire-tools.conf" ]; then
+	echo "no configuration file found" >&2
+	exit 1
+fi
+$cmd "${binary_dir}/mediafire-shell" -c "help; ls; whoami"