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Regex how to match an optional character
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Use
[A-Z]?
to make the letter optional. {1} is redundant. (Of course you could also write [A-Z]{0,1} which would mean the same, but that's what the ? is there for.)
You could improve your regex to
^([0-9]{5})+\s+([A-Z]?)\s+([A-Z])([0-9]{3})([0-9]{3})([A-Z]{3})([A-...
How to check if a process id (PID) exists
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10 Answers
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Gradle, “sourceCompatibility” vs “targetCompatibility”?
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81
targetCompatibility and sourceCompatibility maps to -target release and -source release in javac...
How to find out if an installed Eclipse is 32 or 64 bit version?
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210
Hit Ctrl+Alt+Del to open the Windows Task manager and switch to the processes tab.
32-bit prog...
C语言结构体里的成员数组和指针 - C/C++ - 清泛网 - 专注C/C++及内核技术
...码copy过去编译和调试，我把代码列在下面：
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#include <stdio.h>
struct str{
int len;
char s[0];
};
struct foo {
struct str *a;
};
int main(int argc, ...
How can I get a count of the total number of digits in a number?
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16 Answers
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Sass .scss: Nesting and multiple classes?
...ements and -classes:
.element{
&:hover{ ... }
&:nth-child(1){ ... }
}
However, you can place the & at virtually any position you like*, so the following is possible too:
.container {
background:red;
#id &{
background:blue;
}
}
/* compiles to: */
.conta...
Piping both stdout and stderr in bash?
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172
(Note that &>>file appends to a file while &> would redirect and overwrite a ...