Add gpioget command

src/cmd/get.zig

@@ -0,0 +1,55 @@
+const std = @import("std");
+const gpio = @import("gpio");
+
+pub fn main() !void {
+    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
+    defer std.debug.assert(gpa.deinit() == .ok);
+    const alloc = gpa.allocator();
+
+    var args = try std.process.argsAlloc(alloc);
+    defer std.process.argsFree(alloc, args);
+
+    const stdout = std.io.getStdOut().writer();
+
+    if (args.len < 3) {
+        try stdout.print("Usage: {s} <gpiochip> <line...>\n\n", .{args[0]});
+        return error.InsufficientArguments;
+    }
+
+    var path: []const u8 = if (hasPrefix(args[1], "gpiochip"))
+        try std.mem.concat(alloc, u8, &.{ "/dev/", args[1] })
+    else
+        try std.mem.concat(alloc, u8, &.{ "/dev/gpiochip", args[1] });
+    defer alloc.free(path);
+
+    var chip = try gpio.getChip(path);
+    defer chip.close();
+    try chip.setConsumer("gpioget");
+
+    var offsets = std.ArrayList(u32).init(alloc);
+    defer offsets.deinit();
+
+    // Iterate over each argument starting from the second one
+    for (args[2..args.len]) |argument| {
+        // Parse each argument as an integer and add it to offsets
+        var offset = try std.fmt.parseInt(u32, argument, 10);
+        try offsets.append(offset);
+    }
+
+    var lines = try chip.requestLines(offsets.items, .{ .input = true });
+    defer lines.close();
+    const vals = try lines.getValues();
+
+    var i: u32 = 0;
+    while (i < args.len - 2) : (i += 1) {
+        const value: u1 = if (vals.isSet(i)) 1 else 0;
+        try stdout.print("{d} ", .{value});
+    }
+
+    try stdout.writeByte('\n');
+}
+
+fn hasPrefix(s: []const u8, prefix: []const u8) bool {
+    if (s.len < prefix.len) return false;
+    return (std.mem.eql(u8, s[0..prefix.len], prefix));
+}