zig/doc/langref/std_options.zig

/// The presence of this declaration allows the program to override certain behaviors of the standard library.
/// For a full list of available options, see the documentation for `std.Options`.
pub const std_options: std.Options = .{
    // By default, in safe build modes, the standard library will attach a segfault handler to the program to
    // print a helpful stack trace if a segmentation fault occurs. Here, we can disable this, or even enable
    // it in unsafe build modes.
    .enable_segfault_handler = true,
    // This is the logging function used by `std.log`.
    .logFn = myLogFn,
};

fn myLogFn(
    comptime level: std.log.Level,
    comptime scope: @EnumLiteral(),
    comptime format: []const u8,
    args: anytype,
) void {
    // We could do anything we want here!
    // ...but actually, let's just call the default implementation.
    std.log.defaultLog(level, scope, format, args);
}

const std = @import("std");

// syntax