Add readvars.c for parsing command line args and shell vars.

Add functions to help simplify parsing of command line arguments as well
as files containing shell-style variables.  These functions will parse
strings where values either stand alone or are of the key=value format.
The idea is to reduce the code surrounding /proc/cmdline handling as
well as add in support for easy parsing of files containing shell
variables (e.g., ifcfg files).

3 files changed, 157 insertions, 2 deletions

diff --git a/loader/Makefile.am b/loader/Makefile.am
index 306ef11d9..0d52fe7b7 100644
--- a/loader/Makefile.am
+++ b/loader/Makefile.am
@@ -54,11 +54,12 @@ loader_SOURCES     = loader.c copy.c moduleinfo.c loadermisc.c \
                      getparts.c dirbrowser.c fwloader.c ibft.c hardware.c \
                      method.c cdinstall.c hdinstall.c nfsinstall.c \
                      urlinstall.c net.c urls.c telnet.c telnetd.c \
-                     rpmextract.c
+                     rpmextract.c readvars.c
 
 init_CFLAGS        = $(COMMON_CFLAGS) $(GLIB_CFLAGS)
 init_LDADD         = $(GLIB_LIBS) $(top_srcdir)/pyanaconda/isys/libisys.la
-init_SOURCES       = init.c undomounts.c shutdown.c copy.c modules.c
+init_SOURCES       = init.c undomounts.c shutdown.c copy.c modules.c \
+                     readvars.c
 
 shutdown_CFLAGS    = $(COMMON_CFLAGS) -DAS_SHUTDOWN=1
 shutdown_SOURCES   = shutdown.c undomounts.c
diff --git a/loader/readvars.c b/loader/readvars.c
new file mode 100644
index 000000000..b45317528
--- /dev/null
+++ b/loader/readvars.c
@@ -0,0 +1,125 @@
+/*
+ * readvars.c
+ * Copyright (C) 2009, 2010  Red Hat, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author(s): David Cantrell <dcantrell@redhat.com>
+ */
+
+#include <stdio.h>
+#include <ctype.h>
+#include <glib.h>
+
+#include "../pyanaconda/isys/log.h"
+
+/*
+ * Given a string with shell-style variables listed (e.g., the contents of an
+ * /etc/sysconfig file), parse the contents and generate a hash table of the
+ * variables read.  Return the hash table to the caller.  Caller is
+ * responsible for freeing memory associated with the hash table:
+ *
+ *     table = readvars_read_conf("VAR1=val1\nVAR2=val2\n");
+ *     g_hash_table_destroy(table);
+ *
+ * Errors encountered during parsing will result in this function returning
+ * NULL.
+ *
+ * Variables can also be standalone (done so this function can parse the
+ * contents of /proc/cmdline).  If they lack a value and are just in the
+ * string as a single token, they will become a hash table key with an
+ * NULL value.
+ */
+GHashTable *readvars_parse_string(gchar *contents) {
+    gint argc = 0, i = 0;
+    gchar **argv = NULL;
+    GError *e = NULL;
+    GHashTable *conf = g_hash_table_new_full(g_str_hash, g_str_equal,
+                                             g_free, g_free);
+
+    if (contents == NULL) {
+        return NULL;
+    }
+
+    if (!g_shell_parse_argv(contents, &argc, &argv, &e)) {
+        if (e != NULL) {
+            logMessage(ERROR, "%s(%d): %s", __func__, __LINE__, e->message);
+            g_error_free(e);
+        }
+
+        return NULL;
+    }
+
+    while (i < argc) {
+        gchar **tokens = g_strsplit(argv[i], "=", 0);
+        guint len = g_strv_length(tokens);
+        gchar *key = NULL, *value = NULL;
+        e = NULL;
+
+        if (len == 1 || len == 2) {
+            key = g_strdup(tokens[0]);
+        }
+
+        if (len == 2) {
+            value = g_shell_unquote(tokens[1], &e);
+
+            if (value == NULL && e != NULL) {
+                logMessage(ERROR, "%s(%d): %s", __func__, __LINE__,
+                           e->message);
+                g_error_free(e);
+            }
+        }
+
+        if (key != NULL) {
+            g_hash_table_insert(conf, key, value);
+        }
+
+        g_strfreev(tokens);
+        i++;
+    }
+
+    g_strfreev(argv);
+    return conf;
+}
+
+/*
+ * Read contents of file and call readvars_parse_string() with that string,
+ * caller is responsible for cleanup in the same style as
+ * readvars_parse_string().
+ */
+GHashTable *readvars_parse_file(gchar *filename) {
+    gsize len = 0;
+    gchar *input = NULL;
+    GError *e = NULL;
+    GHashTable *ret = NULL;
+
+    if (filename == NULL) {
+        return NULL;
+    }
+
+    if (!g_file_get_contents(filename, &input, &len, &e)) {
+        if (e != NULL) {
+            logMessage(ERROR, "%s(%d): %s", __func__, __LINE__, e->message);
+            g_error_free(e);
+        }
+
+        g_free(input);
+        return NULL;
+    }
+
+    ret = readvars_parse_string(input);
+    g_free(input);
+
+    return ret;
+}
diff --git a/loader/readvars.h b/loader/readvars.h
new file mode 100644
index 000000000..8938c04a0
--- /dev/null
+++ b/loader/readvars.h
@@ -0,0 +1,29 @@
+/*
+ * readvars.h
+ * Copyright (C) 2009, 2010  Red Hat, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author(s): David Cantrell <dcantrell@redhat.com>
+ */
+
+#include <glib.h>
+
+#ifndef READVARS_H
+#define READVARS_H
+
+GHashTable *readvars_parse_string(gchar *);
+GHashTable *readvars_parse_file(gchar *);
+
+#endif