sled

чување 3ca053034cccbd059e4b81c5b99f3b17c3b6d217
родитељ 5f862722d79c391d84f8cba0507ee2bd36eb12cc
Аутор: Страхиња Радић <contact@strahinja.org>
Датум:   Wed,  2 Mar 2022 16:08:29 +0100

sled.c(save_file): More sophisticated handling of file mode and symlinks

Signed-off-by: Страхиња Радић <contact@strahinja.org>

Diffstat:
M
sled.c
 | 
64
+++++++++++++++++++++++++++++++++++++++++++++++++---------------

измењених датотека: 1, додавања: 49(+), брисања: 15(-)
diff --git a/sled.c b/sled.c
@@ -36,7 +36,11 @@ enum {
 	SAVE_ERR_NONE		= 0,
 	SAVE_ERR_CANT_ALLOC	= 1,
 	SAVE_ERR_CANT_OPEN_FILE = 2,
-	SAVE_ERR_CANT_MOVE_FILE = 3
+	SAVE_ERR_CANT_MOVE_FILE = 3,
+	SAVE_ERR_CANT_STAT_FILE = 4,
+	SAVE_ERR_CANT_READLINK	= 5,
+	SAVE_ERR_CANT_SYMLINK	= 6,
+	SAVE_ERR_CANT_UNLINK	= 7
 };
 
 extern const char* backup_suffix;
@@ -681,39 +685,59 @@ save_file(struct DrawState* state)
 	char* backup_filename = NULL;
 #endif
 	struct stat st;
+	char* real_filename = NULL;
+	size_t rfn_len	    = 0;
 
-	if (!(buf = calloc(MAXBUFLINE, 1)))
-	{
-		state->running = 0;
+	if (!(buf = calloc(MAXBUFLINE, 1))
+		|| !(real_filename = calloc(MAXPATH, 1)))
 		return SAVE_ERR_CANT_ALLOC;
-	}
 #ifdef CREATE_BACKUPS
 	if (!(backup_filename = calloc(MAXPATH, 1)))
-	{
-		state->running = 0;
 		return SAVE_ERR_CANT_ALLOC;
-	}
 #endif
 
 	strcpy(state->action, actions[ACT_WRITING]);
 	redraw_status(state);
 
 #ifdef CREATE_BACKUPS
-	if (stat(state->filename, &st) != -1)
+	if (lstat(state->filename, &st) != -1)
 	{
+		if (S_ISLNK(st.st_mode))
+		{
+			rfn_len = readlink(state->filename, real_filename,
+				MAXPATH);
+			if (rfn_len == -1)
+				return SAVE_ERR_CANT_READLINK;
+			real_filename[rfn_len] = 0;
+			if (stat(real_filename, &st) == -1)
+				return SAVE_ERR_CANT_STAT_FILE;
+		}
 		strcpy(backup_filename, state->filename);
 		strcat(backup_filename, backup_suffix);
-		if (rename(state->filename, backup_filename) == -1)
-		{
-			strcpy(state->error, errors[SAVE_ERR_CANT_MOVE_FILE]);
+		if (rename(rfn_len > 0 ? real_filename : state->filename,
+			    backup_filename)
+			== -1)
 			return SAVE_ERR_CANT_MOVE_FILE;
-		}
 	}
+	else
+		return SAVE_ERR_CANT_STAT_FILE;
 #endif
 
-	if (!(output = fopen(state->filename, "wt")))
+	if (!(output = fopen(rfn_len > 0 ? real_filename : state->filename,
+		      "wt")))
 		return SAVE_ERR_CANT_OPEN_FILE;
 
+#ifdef CREATE_BACKUPS
+	if (rfn_len > 0)
+	{
+		if (unlink(state->filename) == -1)
+			return SAVE_ERR_CANT_UNLINK;
+		if (symlink(real_filename, state->filename) == -1)
+			return SAVE_ERR_CANT_SYMLINK;
+	}
+	chmod(rfn_len > 0 ? real_filename : state->filename, st.st_mode);
+#endif
+
 	if (state->rows_count == 1 && state->buffer[0].length == 0)
 		goto save_file_cleanup;
 
@@ -729,6 +753,7 @@ save_file_cleanup:
 	free(backup_filename);
 #endif
 	free(buf);
+	free(real_filename);
 	*state->action = 0;
 	return SAVE_ERR_NONE;
 }
@@ -1659,12 +1684,21 @@ write_file(struct DrawState* state)
 		state->running = 0;
 		break;
 	case SAVE_ERR_CANT_MOVE_FILE:
+		strcpy(state->error, errors[ERR_CANT_MOVE]);
+		state->running = 0;
+		break;
+	case SAVE_ERR_CANT_READLINK:
+	case SAVE_ERR_CANT_STAT_FILE:
+	case SAVE_ERR_CANT_SYMLINK:
+	case SAVE_ERR_CANT_UNLINK:
 		strcpy(state->error, strerror(errno));
 		state->running = 0;
 		break;
-	default:
+	case SAVE_ERR_NONE:
 		*state->error = 0;
 		state->dirty  = 0;
+		break;
+	default:;
 	}
 
 	return 0;