Interview question: Write a function to remove the comments in the C/C ++ program code.

Write a function to remove the comments in the C/C ++ program code and return the results.

The following code is compiled in vc6 and tested in the source code file. The comments are removed successfully.

# Include <string. h> <br/> # include <stdlib. h> <br/> # include <stdio. h> <br/> # include <fcntl. h> <br/> # include <Io. h> </P> <p>/** // ** <br/> * function: remove comments from C/C ++ program code <br/> * input: pointer to C/C ++ Code <br/> */</P> <p> void <br/> remove_comment (char * Buf, size_t size) <br/>... {<br/> char * P, * end, C; <br/> char * sq_start, * dq_start; <br/> char * lc_start, * bc_start; <br/> size_t Len; </P> <p> P = Buf; <br/> end = P + Size; </P> <p> sq_start = NULL; <br/> dq_start = NULL; </P> <p> lc_start = NULL; <br/> bc_start = NULL; </P> <p> while (P <End )... {</P> <p> C = * P; </P> <p> switch (c )... {</P> <p> case ''':/** // * single quotes */<br/> If (dq_start | lc_start | bc_start )... {<br/>/** // * ignore single quotes in strings and comments */<br/> P ++; <br/> continue; <br/>}</P> <p> If (sq_start = NULL )... {<br/> sq_start = P ++; </P> <p>} else... {<br/> Len = P ++-sq_start; </P> <p> If (LEN = 2 & * (sq_start + 1) = '/')... {<br/>/** // * ignore single quotes */<br/> continue; <br/>}</P> <p> sq_start = NULL; <br/>}</P> <p> break; </P> <p> case '"': /** // * double quotes */<br/> If (sq_start | lc_start | bc_start )... {<br/>/** // * ignore double quotation marks in characters or comments */<br/> P ++; <br/> continue; <br/>}</P> <p> If (dq_start = NULL )... {<br/> dq_start = P ++; </P> <p>} else... {<br/> If (* (p ++- 1) = '/')... {<br/>/** // * ignore double quotation marks in a string */<br/> continue; <br/>}</P> <p> dq_start = NULL; <br/>}</P> <p> break; </P> <p> case '/': /** // * Diagonal Bar */<br/> If (sq_start | dq_start | lc_start | bc_start )... {<br/>/** // * ignore the Diagonal Bar in a character, string, or comment */<br/> P ++; <br/> continue; <br/>}</P> <p> C = * (p + 1); </P> <p> If (C = '/')... {<br/> lc_start = P; <br/> P + = 2; </P> <p>} else if (C = '*')... {<br/> bc_start = P; <br/> P + = 2; </P> <p>} else... {<br/> P ++; <br/>}</P> <p> break; </P> <p> case '*': /** // * asterisk */<br/> If (sq_start | dq_start | lc_start | bc_start = NULL )... {<br/>/** // * ignore the asterisks in characters, strings, or line comments */<br/> P ++; <br/> continue; <br/>}</P> <p> If (* (p + 1 )! = '/')... {<Br/>/** // * ignore the asterisk in the block comment */<br/> P ++; <br/> continue; <br/>}</P> <p> P + = 2; </P> <p> memset (bc_start, '', p-bc_start ); </P> <p> bc_start = NULL; </P> <p> break; </P> <p> case '': /** // * line break */<br/> If (lc_start = NULL )... {<br/> P ++; <br/> continue; <br/>}</P> <p> C = * (p-1 ); </P> <p> memset (lc_start, '', <br/> (C = ''? (P ++-1): p ++)-lc_start); </P> <p> lc_start = NULL; </P> <p> break; </P> <p> default: <br/> P ++; <br/> break; <br/>}</P> <p> If (lc_start )... {<br/> memset (lc_start, '', p-lc_start ); <br/>}</P> <p> int <br/> main (INT argc, char * argv []) <br/>... {<br/> int FD, N; <br/> char Buf [102400]; </P> <p> FD = open ("C: /Documents and Settings/Administrator/desktop/remove_comment.c ", <br/> _ o_rdonly, 0); <br/> If (FD =-1 )... {<br/> return-1; <br/>}</P> <p> N = read (FD, Buf, sizeof (BUF )); <br/> If (n =-1 | n = 0 )... {<br/> close (FD); <br/> return-1; <br/>}</P> <p> // printf ("test "); </P> <p> remove_comment (BUF, n); </P> <p> * (BUF + n) = '/0 '; <br/> printf (BUF); <br/> close (FD); <br/> return 0; <br/>}</P> <p> this article from the csdn blog, reprinted please indicate the source: http://blog.csdn.net/ngwsx/archive/2008/04/04/2250186.aspx