CMake:在正则表达式中转义变量内的符号 [英] CMake: escaping symbols inside a variable, in regular expressions
问题描述
我尝试用CMake识别带有正则表达式的flexc ++程序的版本。
I try to recognize the version of flexc++ program with regular expressions in CMake.
flexc ++版本的输出类似于:
The ouput of flexc++ version is something like:
prompt$ flexc++ --version
flexc++ V1.01.00
我尝试使用正则表达式提取版本。可执行文件的名称在一个变量中(该变量是其他命令的输出)。问题是flexc ++名称中的字符串 ++。该字符串与符号 +产生冲突(一个或多个匹配项)。小型测试:
I try to extract the version with regular expressions. The name of the executable is in a variable (and this variable is the output of other command). The problem is the string "++" in the flexc++ name. This string create a conflict with the symbol "+" (one or more matchs). A mini test:
set(sample "flexc++ V1.01.00")
set(flexname "flexc++")
string(REGEX REPLACE "^${flexname} V([0-9.]+)$" "\\1"
output "${sample}")
message("${output}")
抛出下一个错误:
RegularExpression::compile(): Nested *?+.
RegularExpression::compile(): Error in compile.
CMake Error at prueba.cmake:4 (string):
string sub-command REGEX, mode REPLACE failed to compile regex "^flexc++
V([0-9.]+)$".
如果我删除了样本和文件名变量中的 ++字符串,它将完美识别版本:
If I erase the "++" string in sample and filename variables, it recognize perfect the version:
set(sample "flexc V1.01.00")
set(flexname "flexc")
string(REGEX REPLACE "^${flexname} V([0-9.]+)$" "\\1"
output "${sample}")
message("${output}")
输出:
1.01.00
问题是 ++字符串。
如何避免此问题?例如,CMake中是否有任何命令,例如:
How can I avoid this problem? For example, are there in CMake any command like:
scape(flexname_scaped ${flexname})
表现
flexname_scaped <-- flexc\\+\\+
?
如何解决此问题?
推荐答案
您可以使用< a href = http://www.cmake.org/cmake/help/v2.8.10/cmake.html#command%3astring rel = nofollow> string(REPLACE ...)
:
You can escape the "++" using string(REPLACE...)
:
string(REPLACE "++" "\\+\\+" flexname_escaped ${flexname})
string(REGEX REPLACE "^${flexname_escaped} V([0-9.]+)$" "\\1"
output "${sample}")
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