vt-is-UTF8 - check whether current VT is in UTF8- or byte-mode. 检查当前VT是否处于VTF8模式或是字节模式.

Posted 2022-02-20 fanweisheng

总览

vt-is-UTF8 [-h|--help] [-V|--version] [-q|--quiet]

 

描述

vt-is-UTF8 checks whether the current VT is in UTF8 mode, by writing (and erasing afterwards) a 3-byte-long UTF8 sequence, and looking how much chars where displayed by the console driver. vt-is-UTF8 检查当前VT是否处于 UTF8 模式, 其方式是写(并且随后擦除) 一个 3 字节的 UTF8 序列, 然后察看控制台驱动展示了多少个字符.

A message telling in which mode the console is is then written to stdout (except if the --quiet option was given). 然后会在标准输出上给出一个信息, 指出控制台所用模式(除非给出了 --quiet 选项).

If the --quiet option is not given, the value returned is 1 if an error occurs, else 0. 在有错误发生时, 如果没有选取 --quiet 选项, 返回值将是 1 , 否则将是 0 .

 

选项

-h --help

display version number, a short help message and exit. 展示版本号, 以及一个简短的帮助信息, 然后退出.

 

-V --version

display version number and exit. 展示版本号然后退出.

 

-q --quiet

do not print on stdout in with mode we are, but return the state as exit-status 1 if in UTF8-mode, 0 if in byte-mode. In case of error, 0 is returned and a message is displayed on stderr. 不在标准输出上打印所处模式, 但是返回一个状态, 对于 UTF8 模式该退出状态为 1 , 而对于字节模式该状态为 0 . 如果发生错误, 也返回 0 , 并且送给标准错误一个信息.

 

BUGS

The check should be done by directly asking the kernel, which is not possible as of kernels 2.0.x. 模式的检查可能应该通过直接请求内核来进行, 但从内核 2.0.x 开始这就不可能了.

As of kernel 2.0.35, the byte-mode is sometimes erroneously detected as UTF8-mode, after switching from a 512-chars font to a 256-chars font. This is probably a console-driver bug. 从 2.0.35 的内核开始, 在做了从 512 字符字体到 256 字符字体的切换后, 字节模式有时会被错误地认为是 UTF8 模式. 这或许就是一个控制台驱动的 bug .