Initial commit

libsst-os/SST_FileSys_POSIX.c

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+/*
+        SST_FileSys_POSIX.c
+        Author: Patrick Baggett <ptbaggett@762studios.com>
+        Created: 3/31/2012
+
+        Purpose: 
+
+        libsst-os file system querying for POSIX systems
+
+        License:
+
+        This program is free software. It comes without any warranty, to
+        the extent permitted by applicable law. You can redistribute it
+        and/or modify it under the terms of the Do What The Fuck You Want
+        To Public License, Version 2, as published by Sam Hocevar. See
+        http://sam.zoy.org/wtfpl/COPYING for more details.
+
+*/
+
+#include <SST/SST_FileSys.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <limits.h>
+#include <dirent.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+
+/* In order to get alloca() on Solaris, <alloca.h> is needed */
+#if defined(__SUNPRO_C)
+	#include <alloca.h>
+#endif
+
+/* No PATH_MAX symbol */
+#if !defined(PATH_MAX)
+
+	#if defined(_POSIX_PATH_MAX) && 
+		#define PATH_MAX _POSIX_PATH_MAX
+	#else
+		#define PATH_MAX 256 /* This is what _POSIX_PATH_MAX must be according to POSIX */
+	#endif
+#endif
+
+typedef struct SST_Dir_POSIX
+{
+	char* canonPath;
+	size_t canonPathLen;
+	DIR* dirp;
+} SST_Dir_POSIX;
+
+SST_Dir SST_OS_OpenDirectory(const char* path)
+{
+	size_t len;
+	char* canonPath;
+	SST_Dir_POSIX* dh;
+	DIR* dirp;
+
+	/* Ensure no trailing slash */
+	len = strlen(path);
+	if(len == 0 || path[len-1] == '/')
+		return NULL;
+
+	/* Out of memory? */
+	canonPath = (char*)malloc(PATH_MAX);
+	if(!canonPath)
+		return NULL;
+
+	/* Allocate directory handle */
+	dh = (SST_Dir_POSIX*)malloc(sizeof(SST_Dir_POSIX));
+	if(!dh)
+	{
+		free(canonPath);
+		return NULL;
+	}
+	
+	/* Remove garbage "." and ".." from path, get canonical form */
+	if(!realpath(path, canonPath))
+	{	
+		free(canonPath);
+		free(dh);
+		return NULL;
+	}
+	
+	/* Attempt to open directory */
+	dirp = opendir(canonPath);
+	if(!dirp)
+	{
+		free(canonPath);
+		free(dh);
+		return NULL;
+	}
+
+	dh->canonPathLen = strlen(canonPath);
+	dh->canonPath = canonPath;
+	dh->dirp = dirp;
+	
+	return (SST_Dir)dh;
+}
+
+int SST_OS_ReadNextDirectoryEntry(SST_Dir dir, SST_FileInfo* fileInfoReturn)
+{
+	SST_Dir_POSIX* dh = (SST_Dir_POSIX*)dir;
+	struct dirent* ent;
+	size_t len;
+	char* tmp;
+	struct stat statbuf;
+	
+	/* Read next directory entry */
+	ent = readdir(dh->dirp);
+	if(!ent)
+		return 0;
+	
+	/* Ignore "." and ".." */
+	if(strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0)
+			return SST_OS_ReadNextDirectoryEntry(dir, fileInfoReturn);
+		
+	len = strlen(ent->d_name);
+	if(len >= SST_FILENAME_MAX)
+		len = SST_FILENAME_MAX-1;
+			
+	memcpy(fileInfoReturn->name, ent->d_name, len);
+	fileInfoReturn->name[len] = 0;
+	fileInfoReturn->nameLen = len;
+
+	tmp = (char*)alloca(dh->canonPathLen + len + 2); /* +2 because of "/" character and NULL */
+		
+	/* Construct `canonPath` + '/' + `ent->d_name` + '\0' */
+	memcpy(tmp, dh->canonPath, dh->canonPathLen);
+	tmp[dh->canonPathLen] = '/';
+	memcpy(&tmp[dh->canonPathLen+1], ent->d_name, len);
+	tmp[dh->canonPathLen+1+len] = '\0';
+	
+	if(stat(tmp, &statbuf) == 0)
+	{
+
+		/* Save result */
+		fileInfoReturn->isDir = S_ISDIR(statbuf.st_mode);
+		fileInfoReturn->size = (fileInfoReturn->isDir ? 0 : (size_t)statbuf.st_size);
+	}
+	else /* can't stat() file, so not really much to say about it */
+	{
+		fileInfoReturn->isDir = 0;
+		fileInfoReturn->size = 0;
+	}
+	
+	return (ent != NULL);
+}
+
+
+void SST_OS_CloseDirectory(SST_Dir dir)
+{
+	SST_Dir_POSIX* dh = (SST_Dir_POSIX*)dir;
+	closedir(dh->dirp);
+	free(dh->canonPath);
+	free(dh);
+}
+
+int SST_OS_CreateDirectory(const char* dir)
+{
+	/* Make a directory for anyone to read/write. */
+	if(mkdir(dir, 0777) == 0)
+		return 0; /* Success */
+
+	if(errno == EEXIST)
+	{
+		/* This could refer to a file by the same name, so check to
+		see if it is really a directory. */
+		struct stat statbuf;
+	
+		if(stat(dir, &statbuf) == 0)
+		{
+			/* It really is a directory. Return positive to signal
+			that the directory already exists. */
+			if(S_ISDIR(statbuf.st_mode))
+				return 1;
+		}
+	}
+
+	/* Other error -> failure */
+	return -1;
+}
+
+/******************************************************************************/
+
+int SST_OS_RemoveDirectory(const char* dir)
+{
+	return (rmdir(dir) == 0);
+}
+