请问，为什么在每个程序开头都有<stdio.h>，而我在C语言目录下又找不到。

请问，这是为什么，<stdio.h>又是干什么用的

<stdio.h>头文件包含有printf和scanf函数，在C语言中，可以允许不包含而直接使用这两个函数，但在C++中（其实应该说C++编译器中），必须包含才能找到函数来使用。

stdio.h 即然是文件，我就应该能找到。 为什么，在C语言目录下找不到呢？

不知道你为什么没找到啊

/* stdio.h

Definitions for stream input/output.

Copyright (c) Borland International 1987,1988 All Rights Reserved. */ #if __STDC__ #define _Cdecl #else #define _Cdecl cdecl #endif

#if !defined(__STDIO_DEF_) #define __STDIO_DEF_

#ifndef _SIZE_T #define _SIZE_T typedef unsigned size_t; #endif #ifndef NULL # if defined(__TINY__) || defined(__SMALL__) || defined(__MEDIUM__) # define NULL 0 # else # define NULL 0L # endif #endif

#if !defined(__STDARG) #include <stdarg.h> #endif

/* Definition of the file position type */ typedef long fpos_t;

/* Definition of the control structure for streams */ typedef struct { short level; /* fill/empty level of buffer */ unsigned flags; /* File status flags */ char fd; /* File descriptor */ unsigned char hold; /* Ungetc char if no buffer */ short bsize; /* Buffer size */ unsigned char *buffer; /* Data transfer buffer */ unsigned char *curp; /* Current active pointer */ unsigned istemp; /* Temporary file indicator */ short token; /* Used for validity checking */ } FILE; /* This is the FILE object */

/* Bufferisation type to be used as 3rd argument for "setvbuf" function */ #define _IOFBF 0 #define _IOLBF 1 #define _IONBF 2

/* "flags" bits definitions */ #define _F_RDWR 0x0003 /* Read/write flag */ #define _F_READ 0x0001 /* Read only file */ #define _F_WRIT 0x0002 /* Write only file */ #define _F_BUF 0x0004 /* Malloc'ed Buffer data */ #define _F_LBUF 0x0008 /* line-buffered file */ #define _F_ERR 0x0010 /* Error indicator */ #define _F_EOF 0x0020 /* EOF indicator */ #define _F_BIN 0x0040 /* Binary file indicator */ #define _F_IN 0x0080 /* Data is incoming */ #define _F_OUT 0x0100 /* Data is outgoing */ #define _F_TERM 0x0200 /* File is a terminal */

/* End-of-file constant definition */ #define EOF (-1) /* End of file indicator */

/* Number of files that can be open simultaneously */ #define OPEN_MAX 20 /* Total of 20 open files */ #define SYS_OPEN 20

/* Default buffer size use by "setbuf" function */ #define BUFSIZ 512 /* Buffer size for stdio */

/* Size of an arry large enough to hold a temporary file name string */ #define L_ctermid 5 /* CON: plus null byte */ #define L_tmpnam 13 /* tmpnam buffer size */

/* Constants to be used as 3rd argument for "fseek" function */ #define SEEK_CUR 1 #define SEEK_END 2 #define SEEK_SET 0

/* Number of unique file names that shall be generated by "tmpnam" function */ #define TMP_MAX 0xFFFF

/* Standard I/O predefined streams */ extern FILE _Cdecl _streams[];

#define stdin (&_streams[0]) #define stdout (&_streams[1]) #define stderr (&_streams[2]) #define stdaux (&_streams[3]) #define stdprn (&_streams[4])

void _Cdecl clearerr (FILE *stream); int _Cdecl fclose (FILE *stream); int _Cdecl fflush (FILE *stream); int _Cdecl fgetc (FILE *stream); int _Cdecl fgetpos (FILE *stream, fpos_t *pos); char *_Cdecl fgets (char *s, int n, FILE *stream); FILE *_Cdecl fopen (const char *path, const char *mode); int _Cdecl fprintf (FILE *stream, const char *format, ...); int _Cdecl fputc (int c, FILE *stream); int _Cdecl fputs (const char *s, FILE *stream); size_t _Cdecl fread (void *ptr, size_t size, size_t n, FILE *stream); FILE *_Cdecl freopen (const char *path, const char *mode, FILE *stream); int _Cdecl fscanf (FILE *stream, const char *format, ...); int _Cdecl fseek (FILE *stream, long offset, int whence); int _Cdecl fsetpos (FILE *stream, const fpos_t *pos); long _Cdecl ftell (FILE *stream); size_t _Cdecl fwrite (const void *ptr, size_t size, size_t n, FILE *stream); char *_Cdecl gets (char *s); void _Cdecl perror (const char *s); int _Cdecl printf (const char *format, ...); int _Cdecl puts (const char *s); int _Cdecl rename (const char *oldname, const char *newname); void _Cdecl rewind (FILE *stream); int _Cdecl scanf (const char *format, ...); void _Cdecl setbuf (FILE *stream, char *buf); int _Cdecl setvbuf (FILE *stream, char *buf, int type, size_t size); int _Cdecl sprintf (char *buffer, const char *format, ...); int _Cdecl sscanf (const char *buffer, const char *format, ...); char *_Cdecl strerror (int errnum); FILE *_Cdecl tmpfile (void); char *_Cdecl tmpnam (char *s); int _Cdecl ungetc (int c, FILE *stream); int _Cdecl vfprintf (FILE *stream, const char *format, va_list arglist); int _Cdecl vfscanf (FILE *stream, const char *format, va_list arglist); int _Cdecl vprintf (const char *format, va_list arglist); int _Cdecl vscanf (const char *format, va_list arglist); int _Cdecl vsprintf (char *buffer, const char *format, va_list arglist); int _Cdecl vsscanf (const char *buffer, const char *format, va_list arglist);

#if !__STDC__ int _Cdecl fcloseall(void); FILE *_Cdecl fdopen (int handle, char *type); int _Cdecl fgetchar (void); int _Cdecl flushall (void); int _Cdecl fputchar (int c); int _Cdecl getw (FILE *stream); int _Cdecl putw (int w, FILE *stream); char *_Cdecl _strerror(const char *s); int _Cdecl unlink (const char *path);

#endif

int _Cdecl _fgetc (FILE *stream); /* used by getc() macro */ int _Cdecl _fputc (char c, FILE *stream); /* used by putc() macro */

/* The following macros provide for common functions */

#define ferror(f) ((f)->flags & _F_ERR) #define feof(f) ((f)->flags & _F_EOF) #define fileno(f) ((f)->fd) #define remove(path) unlink(path)

#define getc(f) \ ((--((f)->level) >= 0) ? (unsigned char)(++(f)->curp)[-1] : \ _fgetc (f)) #define putc(c,f) \ ((++((f)->level) < 0) ? (unsigned char)((++(f)->curp)[-1]=(c)) : \ _fputc ((c),f))

#define getchar() getc(stdin) #define putchar(c) putc((c), stdout)

#define ungetc(c,f) ungetc((c),f) /* traditionally a macro */

#endif

那是因为你的C编辑器设置的路径有点问题，如果你是TC的话，可以参照这个帖子来改

http://bbs.bc-cn.net/bbs/dispbbs.asp?boardID=197&ID=3227&page=1

小弟,在这里谢谢各位高手为我指点

这里没有高手， We are team work! (go go go! fire in the hole! cover me!)

[此贴子已经被作者于2004-07-25 12:24:56编辑过]