命令之后这些符号“$ @”> / dev / null 2>＆1“是什么意思？
我最近在这里找到了解决我问题的方法，但是我无法完全理解这个命令中的所有内容意味着什么：
xdg-open "$@">/dev/null 2>&1 “$ @”
"$@"相当于"$1" "$2" ... （命令的位置参数，当参数中有特殊字符时，例如空格，可以使用）。
来自man bash ：
Special Parameters The shell treats several parameters specially. These parameters may only be referenced; assignment to them is not allowed. * Expands to the positional parameters, starting from one. When the expansion is not within double quotes, each positional parameter expands to a separate word. In contexts where it is performed, those words are subject to further word splitting and pathname expansion. When the expansion occurs within double quotes, it expands to a single word with the value of each parameter separated by the first character of the IFS special variable. That is, "$*" is equivalent to "$1c$2c...", where c is the first character of the value of the IFS variable. If IFS is unset, the parameters are separated by spaces. If IFS is null, the parameters are joined without intervening separators. @ Expands to the positional parameters, starting from one. When the expansion occurs within double quotes, each parameter expands to a separate word. That is, "$@" is equivalent to "$1" "$2" ... If the double-quoted expansion occurs within a word, the expansion of the first parameter is joined with the beginning part of the origi‐ nal word, and the expansion of the last parameter is joined with the last part of the original word. When there are no positional parameters, "$@" and $@ expand to nothing (ie, they are removed).
>
将标准输出重定向到文件
的/ dev / null的
特殊文件意味着输出将被“重定向”，换句话说就是不在任何地方写入。
有关详细信息，请参阅man null 。
2>
将错误输出重定向到文件
2>＆1
将错误输出重定向到标准输出
来自man bash ：
Note that the order of redirections is significant. For example, the com‐ mand ls > dirlist 2>&1 directs both standard output and standard error to the file dirlist, while the command ls 2>&1 > dirlist directs only the standard output to file dirlist, because the standard error was duplicated from the standard output before the standard output was redirected to dirlist.
-
"$@"：脚本或函数调用的所有参数。 -
>：表示重定向stdout（与1>相同）。 -
>/dev/null：表示将stdout重定向到/dev/null，这意味着只删除输出。 -
2>&1重定向errout（2>）到stdout（&1）。