1 files changed, 125 insertions, 0 deletions
diff --git a/src/paths.zig b/src/paths.zig
new file mode 100644
index 0000000..b64ff04
--- /dev/null
+++ b/src/paths.zig
@@ -0,0 +1,125 @@
+const std = @import("std");
+const Allocator = std.mem.Allocator;
+const ArrayList = std.ArrayList;
+
+pub fn formatDosPath(allocator: Allocator, path: []const u8) ![]const u8 {
+    var result = ArrayList(u8).init(allocator);
+    defer result.deinit();
+
+    // Convert path to DOS format with uppercase drive letter and backslashes
+    var converted_path = ArrayList(u8).init(allocator);
+    defer converted_path.deinit();
+
+    for (path) |ch| {
+        if (ch == '/') {
+            try converted_path.append('\\');
+        } else {
+            try converted_path.append(std.ascii.toUpper(ch));
+        }
+    }
+
+    // Split into components and convert each to 8.3 format
+    var it = std.mem.splitScalar(u8, converted_path.items, '\\');
+    var first = true;
+
+    while (it.next()) |component| {
+        if (component.len == 0) continue;
+
+        if (!first) {
+            try result.append('\\');
+        }
+        first = false;
+
+        // Convert component to 8.3 format
+        const short_name = try convertTo83(allocator, component);
+        defer allocator.free(short_name);
+        try result.appendSlice(short_name);
+    }
+
+    // Ensure it starts with a drive letter if it's an absolute path
+    if (result.items.len == 0 or (result.items.len >= 1 and result.items[0] == '\\')) {
+        var prefixed = ArrayList(u8).init(allocator);
+        defer prefixed.deinit();
+        try prefixed.appendSlice("C:");
+        if (result.items.len > 0 and result.items[0] != '\\') {
+            try prefixed.append('\\');
+        }
+        try prefixed.appendSlice(result.items);
+        return allocator.dupe(u8, prefixed.items);
+    }
+
+    return allocator.dupe(u8, result.items);
+}
+
+pub fn convertTo83(allocator: Allocator, filename: []const u8) ![]const u8 {
+    // Handle special directories
+    if (std.mem.eql(u8, filename, ".") or std.mem.eql(u8, filename, "..")) {
+        return allocator.dupe(u8, filename);
+    }
+
+    // Handle drive letters (like C:)
+    if (filename.len == 2 and filename[1] == ':') {
+        return allocator.dupe(u8, filename);
+    }
+
+    // Split filename and extension
+    var name_part: []const u8 = filename;
+    var ext_part: []const u8 = "";
+
+    if (std.mem.lastIndexOf(u8, filename, ".")) |dot_pos| {
+        if (dot_pos > 0) { // Don't treat leading dot as extension separator
+            name_part = filename[0..dot_pos];
+            ext_part = filename[dot_pos + 1 ..];
+        }
+    }
+
+    // Clean name part (remove spaces and invalid chars, convert to uppercase)
+    var clean_name = ArrayList(u8).init(allocator);
+    defer clean_name.deinit();
+
+    for (name_part) |ch| {
+        if (std.ascii.isAlphanumeric(ch)) {
+            try clean_name.append(std.ascii.toUpper(ch));
+        } else if (ch == '-' or ch == '_') {
+            try clean_name.append(ch);
+        }
+        // Skip spaces and other invalid characters
+    }
+
+    // Clean extension part (max 3 chars, uppercase)
+    var clean_ext = ArrayList(u8).init(allocator);
+    defer clean_ext.deinit();
+
+    for (ext_part) |ch| {
+        if (clean_ext.items.len >= 3) break;
+        if (std.ascii.isAlphanumeric(ch)) {
+            try clean_ext.append(std.ascii.toUpper(ch));
+        }
+    }
+
+    // Build 8.3 filename
+    var result = ArrayList(u8).init(allocator);
+    defer result.deinit();
+
+    if (clean_name.items.len <= 8 and clean_ext.items.len <= 3) {
+        // Name fits in 8.3, use as-is
+        try result.appendSlice(clean_name.items);
+        if (clean_ext.items.len > 0) {
+            try result.append('.');
+            try result.appendSlice(clean_ext.items);
+        }
+    } else {
+        // Need to abbreviate with ~1
+        const max_name_len = if (clean_name.items.len > 6) 6 else clean_name.items.len;
+        try result.appendSlice(clean_name.items[0..max_name_len]);
+        try result.appendSlice("~1");
+
+        if (clean_ext.items.len > 0) {
+            try result.append('.');
+            const max_ext_len = if (clean_ext.items.len > 3) 3 else clean_ext.items.len;
+            try result.appendSlice(clean_ext.items[0..max_ext_len]);
+        }
+    }
+
+    return allocator.dupe(u8, result.items);
+}