求教文本中换行符的ascii码是多少

alvas

教文本中换行符的ascii码是多少？我编了个程序，要判断文本中的行数，我想知道换行符的ascii码是多少？是10(LF)吗？

mingfal

'\n'就行，不用知道ascii码吧。

yetop

10   换行
13   回车

haohao_h

int value = (int)'\n';
printf("%d",value);

gnap

呵呵！～获取这个的方法有很多种，我这里有一种
[gnap@osiris tmp]$ cat > aaa.txt

[gnap@osiris tmp]$ cat aaa.txt

[gnap@osiris tmp]$ hexdump -C aaa.txt
00000000  0a                                                |.|
00000001
[gnap@osiris tmp]$

于是，显然回车是0x0a也就是ASCII码的13。

alvas

换行和回车有什么区别

manphiz

0x0a(十进制10)是换行，0x0d(十进制13)是回到行首。
这牵扯到Unix格式和DOS格式的一个不同：
在DOS中，只使用0x0a的话，光标只是到下一行相同的列，而不会回到行首。因此，在DOS下，回车包含两个字符：0x0d 0x0a
在Unix中，0x0a一个字符就完成了到下一行行首的整个动作，而不需要0x0d。

因此DOS和Unix之间需要文本转换才能在另一个平台下正确显示回车。

Post by gnap
于是，显然回车是0x0a也就是ASCII码的13。

0x0a=13!!??
那0x0d等于多少？？

jetking

man ascii

有man都不用，太浪费了

zhllg

From Practical C Progarmming: The End-of-Line Puzzle
Back in the dark ages BC (Before Computers), a magical device called a Teletype
Model 33 existed. This amazing machine contained a shift register made out of a
motor, with a rotor, and a keyboard ROM consisting solely of levers and springs. It
contained a keyboard, a printer, and a paper tape reader/punch. It could transmit
messages over the phones using a modem at the rate of 10 characters a second.
The Teletype had a problem. It took two-tenths of a second to move the printhead
from the right side to the left. Two-tenths of a second is two character times. If a
second character came while the printhead was in the middle of a return, that
character was lost.
The Teletype people solved this problem by making end-of-line two characters:
<RETURN> to position the printhead at the left margin and <LINE FEED> to move
the paper up one line.
When the early computers came out, some designers realized that using two
characters for end-of-line wasted storage (at this time, storage was very expensive).
Some picked <LINE FEED> for their end-of-line, some <RETURN>. Some of the
diehards stayed with the two -character sequence.
UNIX uses <LINE FEED> for end-of-line. The newline character, \n, is code 0x0A
(LF or <LINE FEED>). MS-DOS/Windows uses the two characters: <LINE
FEED><RETURN>. Apple uses <RETURN>.

MatthewGong

谢谢楼上提供的背景资料。
以前知道“UNIX uses <LINE FEED> for end-of-line. The newline character, \n, is code 0x0A
(LF or <LINE FEED>). MS-DOS/Windows uses the two characters: <LINE
FEED><RETURN>. ”，而“Apple uses <RETURN>” 呵呵，读了才知道的。