[悬赏] [请教] C程序, 反斜杠 \ 作为命令行参数，会被当做转义符还是字符反斜杠

rain_fish

lz一点发帖，都是球迷啊。。。

rain_fish

看球的吧。。。

hellioncu

LS在中国么？2：30还在回帖{:3_186:}

没本

1. 这个与C无关，命令行的语法这么规定的，方便如文件名带空格作为参数等特殊情况的表示。
2. argv收到的已经是命令行shell处理并且传入的了，所以反斜杠转义已经完成，得到的是转义之后的结果。
3. 从命令行参数中获得在C字符串表达的\，直接在命令行用\\就可以了。
4. 你可以预处理一遍啊，比如实现一个函数pre_translate( argv[1], out_arg, &out_len )，输出到out_arg，看到\就转成\\；还有一个办法是命令行传入时，直接写成\\\\。

没本

你显然还没把sh/bash的文法和C文法区分清楚。你的命令行是sh/bash文法，argv拿到的就是按C文法处理了。在sh/bash文法里面，\a是无效的，所以\被忽略了。参见：
http://www.gnu.org/software/bash ... ml#Escape-Character

1. 
   
2. 3.1.2.1 Escape Character
   
3. 
   
4. A non-quoted backslash ‘\’ is the Bash escape character. It preserves the literal value of the next character that follows, with the exception of newline. If a \newline pair appears, and the backslash itself is not quoted, the \newline is treated as a line continuation (that is, it is removed from the input stream and effectively ignored).
   

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另外bash还提供了一个语法(注意要用＄'带反斜杠字符串')：
http://www.gnu.org/software/bash ... #ANSI_002dC-Quoting

1. 
   
2. 3.1.2.4 ANSI-C Quoting
   
3. 
   
4. Words of the form ＄'string' are treated specially. The word expands to string, with backslash-escaped characters replaced as specified by the ANSI C standard. Backslash escape sequences, if present, are decoded as follows:
   
5. 
   
6. \a
   
7. alert (bell)
   
8. \b
   
9. backspace
   
10. \e
    
11. \E
    
12. an escape character (not ANSI C)
    
13. \f
    
14. form feed
    
15. \n
    
16. newline
    
17. \r
    
18. carriage return
    
19. \t
    
20. horizontal tab
    
21. \v
    
22. vertical tab
    
23. \\
    
24. backslash
    
25. \'
    
26. single quote
    
27. \"
    
28. double quote
    
29. \nnn
    
30. the eight-bit character whose value is the octal value nnn (one to three digits)
    
31. \xHH
    
32. the eight-bit character whose value is the hexadecimal value HH (one or two hex digits)
    
33. \cx
    
34. a control-x character
    
35. The expanded result is single-quoted, as if the dollar sign had not been present.

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