如何从loopj获取android-async-http的Throwable（错误）？(How do I get the Throwable (error) at android-async-http from loopj?)

 尝试： 
 
echo 'export PATH="$PATH:$GOPATH/bin"' >> ~/.profile
 
 POSIX类shell中的单引号字符串（例如bash ）将其内容视为文字 ，这就是您想要的。 
 
 在这里使用双引号字符串的唯一原因是预先选择性地扩展变量引用 - 这在您的情况下不适用。 
 
 也就是说，这是一个例子： 
 
$ echo "Honey, I'm \"$USER\" and I'm \$HOME."
Honey, I'm "jdoe" and I'm $HOME.
 
 反斜杠转义用于转义应被视为文字的嵌入式"和$实例" 。 
 
 
 至于你试过的： 
 
"export PATH="$PATH:$GOPATH/bin""
 
 实际上是一个字符串连接 ，由3个独立的字符串组成： 
 
 
 
 "export PATH=" ，作为双引号字符串， 不包含$ -prefixed插值元素，扩展为文字export PATH= 
 
 
 $PATH:$GOPATH/bin ，作为一个不带引号的字符串，受到额外的shell扩展 ，这不仅涉及将变量$PATH和$GOPATH到它们各自的值，还应用了字拆分和路径名扩展（globbing） 。 
 
 
 "" ，相当于空字符串，实际上被忽略了。 
 
 
 请注意类似POSIX的shell如何通过将字符串（不带引号或单引号或双引号） 直接放在另一个上来组成更大的字符串（连接字符串）。 

Try:
 
echo 'export PATH="$PATH:$GOPATH/bin"' >> ~/.profile
 
Single-quoted strings in POSIX-like shells (such as bash) treat their content as literals, which is what you want here.
 
The only reason to use a double-quoted string here would be to selectively expand variable references up front - which doesn't apply in your case.
 
That said, here's an example:
 
$ echo "Honey, I'm \"$USER\" and I'm \$HOME."
Honey, I'm "jdoe" and I'm $HOME.
 
Backslash-escaping is used to escape embedded " and $ instances that should be treated as literals.
 
 
As for what you tried:
 
"export PATH="$PATH:$GOPATH/bin""
 
is actually a string concatentation, composed of 3 separate strings:
 
 
 
"export PATH=", which, as a double-quoted string that happens not to contains $-prefixed interpolation elements, expands to literal export PATH=
 
 
$PATH:$GOPATH/bin, which, as an unquoted string, is subject to additional shell expansions, which not only involves expanding variables $PATH and $GOPATH to their respective values, but also applies word-splitting and pathname expansion (globbing).
 
 
"", which amounts to the empty string and is effectively ignored.
 
 
Note how POSIX-like shells allow you to compose larger strings (concatenate strings) by placing strings - unquoted or single-quoted or double-quoted - directly next to one another.