# HG changeset patch
# User Jonathan Pevarnek <pevarnj@gmail.com>
# Date 1302234303 14400
# Node ID 3acc1f944c7b6c2ec6d144b9d40959c501495723
# Parent  f806eec33c454c0f1ca72c877bd652b7682a56a1
Added more functionality to the filesystem file

printFname is a nice wrapper for putline that handles filenames, it is really
quite useless

getFname is a nice wrapper for getline to read in a filename assuming there is
an array of (really at least but...) 28 characters

fnameCmp comparies two filenames

fnameLookup find a filename within an array of Direntrys

diff -r f806eec33c45 -r 3acc1f944c7b src/fs.c
--- a/src/fs.c	Thu Apr 07 23:07:46 2011 -0400
+++ b/src/fs.c	Thu Apr 07 23:45:03 2011 -0400
@@ -26,6 +26,8 @@
 };
 typedef struct DIRENTRY Direntry;
 
+//REQUIRES:   fsBlock points to an object with size at least 1024
+//EFFECTS:    Sets fsBlock to be equal
 int readFSBlock(u32 dev, u32 blkno, void *fsBlock)
 {
 	if(fba_read_blk(dev, blkno*2, fsBlock)) return 1;
@@ -33,19 +35,53 @@
 	return 0;
 }
 
+void printFname(char *name)
+{
+	putline(name, 28);
+}
+
+//Sets name to contain a filename entered by the user
+//REQUIRES:   name is 28 characters long
+void getFname(char *fname)
+{
+	int chars = getline(fname, 28);
+	for(;chars < 28; chars++) {
+		fname[chars] = ' ';
+	}
+}
+
+//Checks whether two file names are equal
+int fnameCmp(const char *a, const char *b)
+{
+	int i;
+	for(i = 0; i < 28; i++, a++, b++) {
+		if(*a - *b) return *a - *b;
+	}
+	return 0;
+}
+
+//Finds the item within an array of filenames with the same name as fname
+int fnameLookup(char *fname, const Direntry array[], int last)
+{
+	int i;
+	for(i = 0; i < last; i++)
+		if(!fnameCmp(fname, array[i].fname)) return i;
+	return last;
+}
+
 void start(u64 __memsize)
 {
 	sPrint(""); //I have no idea why I would possibly need this...
-//	char buffer[256];
+	char buffer[256];
 	
 	u32 dev = find_dev(0x100);
 	Superblock sb;
-	if(readFSBlock(dev, 1, &sb)) {
+	if(readFSBlock(dev, 1, &sb)) { //get the super block
 		sPrint("ERROR\n");
 		goto END;
 	}
 	Inode root;
-	if(readFSBlock(dev, sb.root_inode, &root)) {
+	if(readFSBlock(dev, sb.root_inode, &root)) { //get the root inode
 		sPrint("ERROR\n");
 		goto END;
 	}
@@ -53,7 +89,7 @@
 		//calculate how many files (assume less than 32 for the moment)
 		//TODO get rid of assumption
 	Direntry direntries[32];
-	if(readFSBlock(dev, root.blocks[0], direntries)) {
+	if(readFSBlock(dev, root.blocks[0], direntries)) { //get the "first 32" files
 		sPrint("ERROR\n");
 		goto END;
 	}
@@ -61,8 +97,13 @@
 	//Prints off the name of each file
 	Direntry *dp;
 	for(dp = direntries; dp - direntries < nFiles; dp++) {
-		putline(dp->fname, 28), sPrint("\n");
+		printFname(dp->fname), sPrint("\n");
 	}
+	char fname[28];
+	sPrint("Please enter the file to read: ");
+	getFname(fname);
+	printFname(fname), sPrint("\n");
+	sPrint(itoa(fnameLookup(fname, direntries, nFiles), buffer, 10)), sPrint("\n");
 
 END:
 	sPrint("DONE\n");