Add g_readdir_entries() to OS calls

common/os_calls.c

@@ -37,6 +37,7 @@
 #define ctid_t id_t
 #endif
 #include <unistd.h>
+#include <dirent.h>
 #include <errno.h>
 #include <netinet/in.h>
 #include <netinet/tcp.h>
@@ -4243,3 +4244,61 @@ g_qsort(void *base, size_t nitems, size_t size,
 {
     qsort(base, nitems, size, compar);
 }
+
+/*****************************************************************************/
+struct list *
+g_readdir(const char *dir)
+{
+    DIR *handle;
+    struct list *result = NULL;
+    struct dirent *dent;
+    int saved_errno;
+
+    errno = 0; // See readdir(3)
+    if ((handle = opendir(dir)) != NULL &&
+            (result = list_create()) != NULL)
+    {
+        result->auto_free = 1;
+        while (1)
+        {
+            errno = 0;
+            dent = readdir(handle);
+            if (dent == NULL)
+            {
+                break; // errno = 0 for end-of-dir, or != 0 for error
+            }
+
+            // Ignore '.' and '..'
+            if (dent->d_name[0] == '.' && dent->d_name[1] == '\0')
+            {
+                continue;
+            }
+            if (dent->d_name[0] == '.' && dent->d_name[1] == '.' &&
+                    dent->d_name[2] == '\0')
+            {
+                continue;
+            }
+
+            if (!list_add_strdup(result, dent->d_name))
+            {
+                // Memory allocation failure
+                errno = ENOMEM;
+                break;
+            }
+        }
+    }
+
+    saved_errno = errno;
+    if (errno != 0)
+    {
+        list_delete(result);
+        result = NULL;
+    }
+    if (handle != NULL)
+    {
+        closedir(handle);
+    }
+    errno = saved_errno;
+
+    return result;
+}

common/os_calls.h

@@ -411,6 +411,19 @@ void
 g_qsort(void *base, size_t nitems, size_t size,
         int (*compar)(const void *, const void *));
 
+/**
+ * Returns a list of the filenames contained within a directory
+ *
+ * @param dir Name of directory
+ * @return list of directory entry names
+ *
+ * If NULL is returned, further information may be available in errno. No
+ * other errors are specifically logged.
+ * The special files '.' and '..' are not returned.
+ */
+struct list *
+g_readdir(const char *dir);
+
 /* glib-style wrappers */
 #define g_new(struct_type, n_structs) \
     (struct_type *) malloc(sizeof(struct_type) * (n_structs))

tests/common/test_os_calls.c

@@ -7,6 +7,7 @@
 #include <sys/time.h>
 #include <sys/resource.h>
 #include <poll.h>
+#include <errno.h>
 
 #include "os_calls.h"
 #include "list.h"
@@ -20,6 +21,9 @@
 // File for testing ro/rw opens
 #define RO_RW_FILE "./test_ro_rw"
 
+// Directory for testing files
+#define TEST_READDIR "./test_readdir"
+
 /******************************************************************************/
 /***
  * Gets the number of open file descriptors for the current process */
@@ -487,6 +491,74 @@ START_TEST(test_g_sck_fd_overflow)
 }
 END_TEST
 
+/******************************************************************************/
+static int qsort_func_strlist(const void *a, const void *b)
+{
+    return strcmp(*(const char **)a, *(const char **)b);
+}
+
+START_TEST(test_g_readdir)
+{
+    int status;
+    const char *entries[] = { "one", "two", "three", "four", "five", 0};
+    unsigned int count = 0;
+    const char **name;
+
+    // Don't check results of create dir, as we may be re-running this
+    // after a fail
+    (void)g_mkdir(TEST_READDIR);
+    // This should work though
+    status = g_set_current_dir(TEST_READDIR);
+    ck_assert_int_eq(status, 0);
+
+    // Create some files in the directory
+    for (name = entries; *name != NULL; ++name, ++count)
+    {
+        int fd = g_file_open_rw(*name);
+        ck_assert(fd >= 0);
+        g_file_close(fd);
+    }
+
+    // Can we read them, and are there the expected number?
+    struct list *dentries = g_readdir(".");
+    ck_assert_ptr_ne(dentries, NULL);
+    ck_assert_ptr_ne(dentries, NULL);
+    ck_assert_int_eq(dentries->count, count);
+
+    // Sort both lists according to the current locale
+    qsort(entries, count, sizeof(entries[0]), qsort_func_strlist);
+    qsort(dentries->items, count, sizeof(dentries->items[0]),
+          qsort_func_strlist);
+
+    // Check both lists are identical
+    int i;
+    for (i = 0 ; i < count; ++i)
+    {
+        ck_assert_str_eq(entries[i], (const char *)dentries->items[i]);
+    }
+
+    // Clean up
+    list_delete(dentries);
+    for (i = 0 ; i < count ; ++i)
+    {
+        g_file_delete(entries[i]);
+    }
+    g_set_current_dir("..");
+    status = g_remove_dir(TEST_READDIR); // Returns a boolean(?)
+    ck_assert_int_ne(status, 0);
+
+
+}
+END_TEST
+
+START_TEST(test_g_readdir_not_dir)
+{
+    struct list *dentries = g_readdir("NoSuchDirectory");
+    ck_assert_ptr_eq(dentries, 0);
+    ck_assert_int_eq(errno, ENOENT);
+}
+END_TEST
+
 /******************************************************************************/
 Suite *
 make_suite_test_os_calls(void)
@@ -512,6 +584,8 @@ make_suite_test_os_calls(void)
     tcase_add_test(tc_os_calls, test_g_file_is_open);
     tcase_add_test(tc_os_calls, test_g_sck_fd_passing);
     tcase_add_test(tc_os_calls, test_g_sck_fd_overflow);
+    tcase_add_test(tc_os_calls, test_g_readdir);
+    tcase_add_test(tc_os_calls, test_g_readdir_not_dir);
 
     // Add other test cases in other files
     suite_add_tcase(s, make_tcase_test_os_calls_signals());