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回复 #21 lululau 的帖子
这个和ls无关哦,是 `` 或 $() 的问题。
- Command Substitution
- Command substitution allows the output of a command to replace the com-
- mand name. There are two forms:
- $(command)
- or
- `command`
- Bash performs the expansion by executing command and replacing the com-
- mand substitution with the standard output of the command, with any
- trailing newlines deleted. Embedded newlines are not deleted, but they
- may be removed during word splitting. The command substitution $(cat
- file) can be replaced by the equivalent but faster $(< file).
- When the old-style backquote form of substitution is used, backslash
- retains its literal meaning except when followed by $, `, or \. The
- first backquote not preceded by a backslash terminates the command sub-
- stitution. When using the $(command) form, all characters between the
- parentheses make up the command; none are treated specially.
- Command substitutions may be nested. To nest when using the backquoted
- form, escape the inner backquotes with backslashes.
- If the substitution appears within double quotes, word splitting and
- pathname expansion are not performed on the results.
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