标准IO函数

 #include <stdio.h>

 

       FILE *fopen(const char *path, const char *mode);

       

The fopen() function opens the file whose name is the string pointed to by path and associates a stream with it.

        

          int fclose(FILE *fp);

 

打开标准I/O流的mode参数

 

 

 

SYNOPSIS

       #include <stdio.h>

 

       size_t fread(void *ptr, size_t size, size_t nmemb, FILE *stream);

 

       size_t fwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream);

 

DESCRIPTION

       The  function  fread()  reads  nmemb  elements of data, each size bytes

       long, from the stream pointed to by stream, storing them at  the  loca‐

       tion given by ptr.

 

       The  function  fwrite()  writes nmemb elements of data, each size bytes

       long, to the stream pointed to by stream, obtaining them from the loca‐

       tion given by ptr.

RETURN VALUE

       fread()  and  fwrite()  return the number of items successfully read or

       written (i.e., not the number of characters).  If an error  occurs,  or

       the  end-of-file is reached, the return value is a short item count (or

       zero).

 

#include <stdio.h>

 

       int fgetc(FILE *stream);

 

       char *fgets(char *s, int size, FILE *stream);

 fgetc() reads the next character from  stream  and  returns  it  as  an

       unsigned char cast to an int, or EOF on end of file or error.

 

 fgets() reads in at most one less than size characters from stream  and

       stores  them  into  the buffer pointed to by s.  Reading stops after an

       EOF or a newline.  If a newline is read, it is stored into the  buffer.

       A  terminating  null  byte ('\0') is stored after the last character in

       the buffer.

 

 #include <stdio.h>

 

       int fputc(int c, FILE *stream);

 

       int fputs(const char *s, FILE *stream);

    fputc() writes the character c, cast to an unsigned char, to stream.

    fputs()  writes  the  string  s to stream, without its terminating null

       byte ('\0').

 

 #include <stdio.h>

 

       int fseek(FILE *stream, long offset, int whence);

 

  The  fseek()  function  sets the file position indicator for the stream

       pointed to by stream.  The new position, measured in bytes, is obtained

       by  adding offset bytes to the position specified by whence.  If whence

       is set to SEEK_SET, SEEK_CUR, or SEEK_END, the offset  is  relative  to

       the  start of the file, the current position indicator, or end-of-file,

       respectively.  A successful call to the  fseek()  function  clears  the

       end-of-file  indicator  for  the  stream  and undoes any effects of the

       ungetc(3) function on the same stream.