Move pgfnames() from libpgport to libpgcommon

It requires pstrdup() from libpgcommon.

src/common/pgfnames.c

@@ -0,0 +1,109 @@
+/*-------------------------------------------------------------------------
+ *
+ * pgfnames.c
+ *	  directory handling functions
+ *
+ * Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *	  src/common/pgfnames.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include <dirent.h>
+
+/*
+ * pgfnames
+ *
+ * return a list of the names of objects in the argument directory.  Caller
+ * must call pgfnames_cleanup later to free the memory allocated by this
+ * function.
+ */
+char	  **
+pgfnames(const char *path)
+{
+	DIR		   *dir;
+	struct dirent *file;
+	char	  **filenames;
+	int			numnames = 0;
+	int			fnsize = 200;	/* enough for many small dbs */
+
+	dir = opendir(path);
+	if (dir == NULL)
+	{
+#ifndef FRONTEND
+		elog(WARNING, "could not open directory \"%s\": %m", path);
+#else
+		fprintf(stderr, _("could not open directory \"%s\": %s\n"),
+				path, strerror(errno));
+#endif
+		return NULL;
+	}
+
+	filenames = (char **) palloc(fnsize * sizeof(char *));
+
+	errno = 0;
+	while ((file = readdir(dir)) != NULL)
+	{
+		if (strcmp(file->d_name, ".") != 0 && strcmp(file->d_name, "..") != 0)
+		{
+			if (numnames + 1 >= fnsize)
+			{
+				fnsize *= 2;
+				filenames = (char **) repalloc(filenames,
+											   fnsize * sizeof(char *));
+			}
+			filenames[numnames++] = pstrdup(file->d_name);
+		}
+		errno = 0;
+	}
+#ifdef WIN32
+
+	/*
+	 * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
+	 * released version
+	 */
+	if (GetLastError() == ERROR_NO_MORE_FILES)
+		errno = 0;
+#endif
+	if (errno)
+	{
+#ifndef FRONTEND
+		elog(WARNING, "could not read directory \"%s\": %m", path);
+#else
+		fprintf(stderr, _("could not read directory \"%s\": %s\n"),
+				path, strerror(errno));
+#endif
+	}
+
+	filenames[numnames] = NULL;
+
+	closedir(dir);
+
+	return filenames;
+}
+
+
+/*
+ *	pgfnames_cleanup
+ *
+ *	deallocate memory used for filenames
+ */
+void
+pgfnames_cleanup(char **filenames)
+{
+	char	  **fn;
+
+	for (fn = filenames; *fn; fn++)
+		pfree(*fn);
+
+	pfree(filenames);
+}