有没有一种简单的方法可以从C/C++源文件中删除注释而无需进行任何预处理.(也就是说,我认为你可以使用gcc -E,但这会扩展宏.)我只想要删除注释的源代码,不应该改变任何其他内容.
编辑:
对现有工具的偏好.我不想用正则表达式自己写这个,我预见代码中有太多的惊喜.
Jos*_*Lee 97
在源文件上运行以下命令:
gcc -fpreprocessed -dD -E test.c
感谢KennyTM寻找合适的旗帜.这是完整性的结果:
test.c的:
#define foo bar
foo foo foo
#ifdef foo
#undef foo
#define foo baz
#endif
foo foo
/* comments? comments. */
// c++ style comments
gcc -fpreprocessed -dD -E test.c:
#define foo bar
foo foo foo
#ifdef foo
#undef foo
#define foo baz
#endif
foo foo
Jon*_*ler 15
这取决于你的评论是多么不正常.我有一个程序scc来删除C和C++注释.我也有一个测试文件,我尝试了GCC(MacOS X上的4.2.1)以及当前选择的答案中的选项 - 而且GCC似乎并没有在一些可怕的屠杀评论中做得很好.测试用例.
考虑测试用例的(子集 - 总共135行中的36个):
/\
*\
Regular
comment
*\
/
The regular C comment number 1 has finished.
/\
\/ This is not a C++/C99 comment!
This is followed by C++/C99 comment number 3.
/\
\
\
/ But this is a C++/C99 comment!
The C++/C99 comment number 3 has finished.
/\
\* This is not a C or C++ comment!
This is followed by regular C comment number 2.
/\
*/ This is a regular C comment *\
but this is just a routine continuation *\
and that was not the end either - but this is *\
\
/
The regular C comment number 2 has finished.
This is followed by regular C comment number 3.
/\
\
\
\
* C comment */
在我的Mac上,GCC(gcc -fpreprocessed -dD -E subset.c)的输出是:
/\
*\
Regular
comment
*\
/
The regular C comment number 1 has finished.
/\
\/ This is not a C++/C99 comment!
This is followed by C++/C99 comment number 3.
/\
\
\
/ But this is a C++/C99 comment!
The C++/C99 comment number 3 has finished.
/\
\* This is not a C or C++ comment!
This is followed by regular C comment number 2.
/\
*/ This is a regular C comment *\
but this is just a routine continuation *\
and that was not the end either - but this is *\
\
/
The regular C comment number 2 has finished.
This is followed by regular C comment number 3.
/\
\
\
\
* C comment */
'scc'的输出是:
The regular C comment number 1 has finished.
/\
\/ This is not a C++/C99 comment!
This is followed by C++/C99 comment number 3.
/\
\
\
/ But this is a C++/C99 comment!
The C++/C99 comment number 3 has finished.
/\
\* This is not a C or C++ comment!
This is followed by regular C comment number 2.
The regular C comment number 2 has finished.
This is followed by regular C comment number 3.
'scc -C'(识别双斜杠注释)的输出是:
The regular C comment number 1 has finished.
/\
\/ This is not a C++/C99 comment!
This is followed by C++/C99 comment number 3.
The C++/C99 comment number 3 has finished.
/\
\* This is not a C or C++ comment!
This is followed by regular C comment number 2.
The regular C comment number 2 has finished.
This is followed by regular C comment number 3.
SCC的当前版本是6.60(日期为2016-06-12),尽管Git版本是在2017-01-18(美国/太平洋时区)创建的.该代码可从GitHub获得,网址为https://github.com/jleffler/scc-snapshots.您还可以找到以前版本(4.03,4.04,5.05)和两个预发行版(6.16,6.50)的快照 - 这些都已标记release/x.yz.
该代码仍主要在RCS下开发.我还在研究如何使用子模块或类似的机制来处理像stderr.c和的公共库文件stderr.h(也可以在https://github.com/jleffler/soq中找到).
SCC版本6.60试图理解C++ 11,C++ 14和C++ 17构造,如二进制常量,数字标点符号,原始字符串和十六进制浮点数.它默认为C11模式操作.(请注意,-C上面提到的标志的含义- 在答案主体和6.60版本中描述的版本4.0x之间翻转,这是当前最新版本.)
gcc -fpreprocessed -dD -E对我不起作用,但是这个程序可以做到:
#include <stdio.h>
static void process(FILE *f)
{
int c;
while ( (c=getc(f)) != EOF )
{
if (c=='\'' || c=='"') /* literal */
{
int q=c;
do
{
putchar(c);
if (c=='\\') putchar(getc(f));
c=getc(f);
} while (c!=q);
putchar(c);
}
else if (c=='/') /* opening comment ? */
{
c=getc(f);
if (c!='*') /* no, recover */
{
putchar('/');
ungetc(c,f);
}
else
{
int p;
putchar(' '); /* replace comment with space */
do
{
p=c;
c=getc(f);
} while (c!='/' || p!='*');
}
}
else
{
putchar(c);
}
}
}
int main(int argc, char *argv[])
{
process(stdin);
return 0;
}
有一个stripcmt程序可以做到这一点:
StripCmt是一个用C编写的简单实用程序,用于从C,C++和Java源文件中删除注释.在Unix文本处理程序的传统中,它可以作为FIFO(先进先出)过滤器或在命令行上接受参数.
(根据hlovdal的回答:关于Python代码的问题)