regex - 为什么 grep 比它应该匹配的更多，例如 "^[\s]*set breakpoint.*in"匹配 "set breakpoint 1 at main.c:5"吗？

Question

模式.txt

^[\s]*set breakpoint.*if
^[\s]*set breakpoint.*in
^[\s]*set breakpoint.*skip

脚本.txt

set breakpoint 1 at main.c:5
set breakpoint 2 at main.c:6
set breakpoint 3 at main.c:7
set breakpoint 4 if

例子和意想不到的结果

当我运行 cat "${script.txt}"| grep -f patterns.txt 结果是:

set breakpoint 1 at main.c:5 // WHY DOES THIS MATCH???
set breakpoint 2 at main.c:6 // WHY DOES THIS MATCH???
set breakpoint 3 at main.c:7 // WHY DOES THIS MATCH???
set breakpoint 4 if

同样适用于:

cat "${script.txt}" | grep -E '^[\s]*set breakpoint.*if|^[\s]*set breakpoint.*in|^[\s]*set breakpoint.*skip'

Answer 1

是因为breakpoint.*in火柴breakpoint <digit> at main在前 3 行( main 以 in 结尾)。

您应该在您的模式中使用结束 anchor ，如下所示:

cat patterns.txt
^\s*set breakpoint.*if$
^s\s*et breakpoint.*in$
^s\s*et breakpoint.*skip$

否则:

^\s*set breakpoint.*i[fn]$
^s\s*et breakpoint.*skip$