從用戶空間傳遞到內核中字符串的長度

當通過proc文件系統向內核傳遞一個字符串時，例如"abcde", 其字符串的長度爲6而不是5， 其中多了一個換行符:

root@android:/ # echo "abcde" >/proc/slab_trace root@android:/ # dmesg
>
><6>[  131.487923] slab_trace_write: slab_trace_name:abcde
><6>[  131.488851] slab_trace_name[i]:97   #'a'
><6>[  131.489011] slab_trace_name[i]:98   #'b'
><6>[  131.489153] slab_trace_name[i]:99   #'c'
><6>[  131.501616] slab_trace_name[i]:100  #'d'
><6>[  131.502286] slab_trace_name[i]:101  #'e'
><6>[  131.502926] slab_trace_name[i]:10    <=== new line character
><6>[  131.503551] slab_trace_name[i]:0    #termination character
><6>[  131.504166] slab_trace_write: slab trace name length: 6 count:6 len:6