Raspberry Pi OS • How do I check the CPU frequency？

Code:

:~ $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freqcat: /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq: No such file or directory:~ $ vcgencmd measure_clockvc_gencmd_read_response returned -1error=2 error_msg="Invalid arguments"