They both mean "new lin开发者_如何学运维e" but when is one used over the other?
\r\n
is a Windows Style
\n
is a POSIX Style
\r
is a old pre-OS X Macs Style, Modern Mac's using POSIX Style.
\r
is a carriage return and \n
is a line feed, in old computers where it not have monitor, have only printer to get out programs result to user, if you want get printing from staring of new line from left, you must get \n
for Line Feed, and \r
for get Carriage return to the most left position, this is from old computers syntax saved to this time on Windows platform.
\n means new line. It means that the cursor must go to the next line.
\r means carriage return. It means that the cursor should go back to the beginning of the line.
Unix programs usually only needs a new line (\n).
Windows programs usually need both.
\n is a newline only, \r\n is a newline and a carriage return (i.e. move the cursor to the left).
'\n' is the default in Unix, '\r\n' is the default in Windows.
Different Operating Systems handle newlines in a different way. Here is a short list of the most common ones: DOS and Windows
They expect a newline to be the combination of two characters, namely '\r\n' (or 13 followed by 10).
Unix (and hence Linux as well)
Unix uses a single '\n' to indicate a new line.
Mac
Macs use a single '\r'.
so this causes problems when u port your app from windows to mac when u're using folder path's and alike.
This is how new line is represented in operating systems Windows (\r\n)and linux (\n)
On Unix the \r is a Carriage Return (CR) and the \n a Line Feed (LF) which together happen to be the be Windows newline identifier and you are replacing them with a Unix newline identifier.
On Windows the \r is a CR, too, but the \n is a combination of CR and LF. So effectively you are trying to replace CR+CR+LF with CR+LF. Doesn't make much sense, does it.
From "perldoc perlop": All systems use the virtual ""\n"" to represent a line terminator, called a "newline". There is no such thing as an unvarying, physical newline character. It is only an illusion that the operating system, device drivers, C libraries, and Perl all conspire to preserve. Not all systems read ""\r"" as ASCII CR and ""\n"" as ASCII LF. For example, on a Mac, these are reversed, and on systems without line terminator, printing ""\n"" may emit no actual data. In general, use ""\n"" when you mean a "newline" for your system, but use the literal ASCII when you need an exact character. For example, most networking protocols expect and prefer a CR+LF (""\015\012"" or ""\cM\cJ"") for line terminators, and although they often accept just ""\012"", they seldom tolerate just ""\015"". If you get in the habit of using ""\n"" for networking, you may be burned some day.
The difference is between different operating systems, on Windows, the newline character is \r\n
while on Linux it is just \n
Mac OSX has just \r
its really just a matter of what the designers of the OS made it to be
In C#, you can just use Environment.NewLine
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