In linux, how does one determine whether the cpu is dual-core or single-core?

In linux, how does one determine whether the cpu is dual-core or single-core-general Linux technology-Linux technology and application information? The following is a detailed description. In linux, you can view the details of each cpu in/proc/cpuinfo.

However, for dual-core CPUs, two CPUs are displayed in cpuinfo. It is often mistaken for two single-core CPUs.

In fact, Physical Processor ID should be used to distinguish between single-core and dual-core. Physical Processor ID can be found in cpuinfo or dmesg.

For example
Root @ debian :~ : 0 # dmesg | grep CPU | grep ID
CPU0: Initial apic id: 0, Physical Processor ID: 0
CPU1: Initial apic id: 1, Physical Processor ID: 0
CPU2: Initial apic id: 6, Physical Processor ID: 3
CPU3: Initial apic id: 7, Physical Processor ID: 3

We can see that this machine has two dual-core CPUs with IDs 0 and 3 respectively.