Ubuntu: o que significa saída de comando de tempo?

Question

A partir do tempo de execução do meu programa, tenho:

real    4m41.679s
user    20m58.623s
sys 0m49.471s

O que essa saída significa? O que é real e o que é usuário?

    

Answer 1

Executando help time no bash:

time: time [-p] pipeline
    Report time consumed by pipeline's execution.

    Execute PIPELINE and print a summary of the real time, user CPU time,
    and system CPU time spent executing PIPELINE when it terminates.

A execução de man 7 time fornece uma descrição de real , user CPU e system CPU time:

Real time is defined as time measured from some fixed point (e.g., the start) in the life of a process (elapsed time).

User CPU time is the time spent executing code in user mode. System CPU time is the time spent by the kernel executing in system mode on behalf of the process (e.g., executing system calls).