:
:
- : , ( c );
- : , ( );
- : , ;
- : , ( );
- : , ( );
- , .
/ :
;
/ ( ), (, );
( ).
() .
() :
o ( ).
o , - .
:
o .
o , -1 .
o () () , , .
o (stderr, stdin, stdout).
o , .
, , ( ), . FILE:
FILE *fp;
( !):
.
(/).
.
.
:
.
.
:
FILE *fopen(char *name, char *mode);
name ,
mode :
| mode | ... | |
| "r" | . , fopen . | ... |
| "w" | . , . , . | ... |
| "a" | . , . | ... |
| "r+" | ( ). . | ... |
| "w+" | . , . | ... |
| "a+" | . , . | ... |
:
|
|
|
| mode | |
| t | ( , ) |
| b |
:
o , \n (Unix) \r, \n (Windows);
o (\n)
:
o .
o / .
:
int fclose(FILE *file_ptr);
(return 0), . ( ).
/ , . fclose() . .
fopen() NULL.
errno (<errno.h>).
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
...
int main()
{
FILE *f = fopen("fil nam .txt", "rt");
if (f == NULL)
{
printf(" %d\n, errno);
exit(1);
}
else
{
//
}
fclose(f);
return 0;
}
, .
1. feof()
int feof(FILE *file_ptr);
feof() , . -.
( ) ,
i = 0;
while (!feof(fp))
{
fgets(buf, sizeof(buf), fp);
printf ("Line %4d: %s", i, buf);
i++;
} //
2. , .
#include <stdio.h>
#include <stdlib.h>
|
|
|
#define MYFILE junk1.txt
int main(void)
{
FILE *fp;
char buf[BUFSIZ] = "Garbage";
int i;
if ((fp = fopen(MYFILE, "r")) == NULL)
{
return (EXIT_FAILURE);
}
i = 0;
while (fgets(buf, sizeof(buf), fp)!= NULL)
{
printf ("Line %4d: %s", i, buf);
i++;
}
fclose(fp);
return(0);
}
| int ftell (FILE * stream); | . -1L. . |
| int fseek(FILE *stream,int offset,int origin); | offset , ORIGIN: SEEK_SET ; SEEK_END ; SEEK_CUR . . "0", . |
| void rewind (FILE * stream); | ( ). , . : fseek(stream, 0L, SEEK_SET); |
| int fflush(FILE *stream); | , . |
.
...
intmain ()
{
FILE * ptrFile = fopen("file.txt","rb");
if (ptrFile == NULL)
exit(1);
else
{
fseek (ptrFile, 0, SEEK _ END); //
long size = ftell(ptrFile); //
fclose (ptrFile); //
}
return 0;
}
