c语言函数--F

函数名: fabs

功 能: 返回浮点数的绝对值

用 法: double fabs(double x);

程序例:

#include <stdio.h> #include <math.h> int main(void) {    float  number = -1234.0;    printf("number: %f  absolute value: %f\n",    number, fabs(number));    return 0; }       

函数名: farcalloc

功 能: 从远堆栈中申请空间

用 法: void far *farcalloc(unsigned long units, unsigned ling unitsz);

程序例:

#include <stdio.h> #include <alloc.h> #include <string.h> #include <dos.h> int main(void) {    char far *fptr;    char *str = "Hello";    /* allocate memory for the far pointer */    fptr = farcalloc(10, sizeof(char));    /* copy "Hello" into allocated memory */    /*       Note: movedata is used because you       might be in a small data model, in       which case a normal string copy routine       can not be used since it assumes the       pointer size is near.    */    movedata(FP_SEG(str), FP_OFF(str),      FP_SEG(fptr), FP_OFF(fptr),             strlen(str));    /* display string (note the F modifier) */    printf("Far string is: %Fs\n", fptr);    /* free the memory */    farfree(fptr);    return 0; }       

函数名: farcoreleft

功 能: 返回远堆中未作用存储区大小

用 法: long farcoreleft(void);

程序例:

#include <stdio.h> #include <alloc.h> int main(void) {    printf("The difference between the\     highest allocated block in the\            far\n");    printf("heap and the top of the far heap\            is: %lu bytes\n", farcoreleft());    return 0; }       

函数名: farfree

功 能: 从远堆中释放一块

用 法: void farfree(void);

程序例:

#include <stdio.h> #include <alloc.h> #include <string.h> #include <dos.h> int main(void) {    char far *fptr;    char *str = "Hello";    /* allocate memory for the far pointer */    fptr = farcalloc(10, sizeof(char));    /* copy "Hello" into allocated memory */    /*       Note: movedata is used because you might be in a small data model,       in which case a normal string copy routine can't be used since it       assumes the pointer size is near.    */    movedata(FP_SEG(str), FP_OFF(str),             FP_SEG(fptr), FP_OFF(fptr),             strlen(str));    /* display string (note the F modifier) */    printf("Far string is: %Fs\n", fptr);    /* free the memory */    farfree(fptr);    return 0; }       

函数名: farmalloc

功 能: 从远堆中分配存储块

用 法: void far *farmalloc(unsigned long size);

程序例:

#include <stdio.h> #include <alloc.h> #include <string.h> #include <dos.h> int main(void) {    char far *fptr;    char *str = "Hello";    /* allocate memory for the far pointer */    fptr = farmalloc(10);    /* copy "Hello" into allocated memory */    /*       Note: movedata is used because we might       be in a small data model, in which case       a normal string copy routine can not be       used since it assumes the pointer size       is near.    */    movedata(FP_SEG(str), FP_OFF(str),      FP_SEG(fptr), FP_OFF(fptr),      strlen(str));    /* display string (note the F modifier) */    printf("Far string is: %Fs\n", fptr);    /* free the memory */    farfree(fptr);    return 0; }       

函数名: farrealloc

功 能: 调整远堆中的分配块

用 法: void far *farrealloc(void far *block, unsigned long newsize);

程序例:

#include <stdio.h> #include <alloc.h> int main(void) {    char far *fptr;    fptr = farmalloc(10);    printf("First address: %Fp\n", fptr);    fptr = farrealloc(fptr,20);    printf("New address  : %Fp\n", fptr);    farfree(fptr);    return 0; }     

函数名: fclose

功 能: 关闭一个流

用 法: int fclose(FILE *stream);

程序例:

#include <string.h> #include <stdio.h> int main(void) {    FILE *fp;    char buf[11] = "0123456789";    /* create a file containing 10 bytes */    fp = fopen("DUMMY.FIL", "w");    fwrite(&buf, strlen(buf), 1, fp);    /* close the file */    fclose(fp);    return 0; }       

函数名: fcloseall

功 能: 关闭打开流

用 法: int fcloseall(void);

程序例:

#include <stdio.h> int main(void) {    int streams_closed;    /* open two streams */    fopen("DUMMY.ONE", "w");    fopen("DUMMY.TWO", "w");    /* close the open streams */    streams_closed = fcloseall();    if (streams_closed == EOF)       /* issue an error message */       perror("Error");    else       /* print result of fcloseall() function */       printf("%d streams were closed.\n", streams_closed);    return 0; }     

函数名: fcvt

功 能: 把一个浮点数转换为字符串

用 法: char *fcvt(double value, int ndigit, int *decpt, int *sign);

程序例:

#include <stdlib.h> #include <stdio.h> #include <conio.h> int main(void) {    char *string;    double value;    int dec, sign;    int ndig = 10;    clrscr();    value = 9.876;    string = ecvt(value, ndig, &dec, &sign);    printf("string = %s      dec = %d \           sign = %d\n", string, dec, sign);    value = -123.45;    ndig= 15;    string = ecvt(value,ndig,&dec,&sign);    printf("string = %s dec = %d sign = %d\n",           string, dec, sign);      value = 0.6789e5; /* scientific                         notation */    ndig = 5;    string = ecvt(value,ndig,&dec,&sign);    printf("string = %s           dec = %d\           sign = %d\n", string, dec, sign);    return 0; }       

函数名: fdopen

功 能: 把流与一个文件句柄相接

用 法: FILE *fdopen(int handle, char *type);

程序例:

#include <sys\stat.h> #include <stdio.h> #include <fcntl.h> #include <io.h> int main(void) {    int handle;    FILE *stream;    /* open a file */    handle = open("DUMMY.FIL", O_CREAT,     S_IREAD | S_IWRITE);    /* now turn the handle into a stream */    stream = fdopen(handle, "w");    if (stream == NULL)       printf("fdopen failed\n");    else    {       fprintf(stream, "Hello world\n");       fclose(stream);    }    return 0; }     

函数名: feof

功 能: 检测流上的文件结束符

用 法: int feof(FILE *stream);

程序例:

#include <stdio.h> int main(void) {    FILE *stream;    /* open a file for reading */    stream = fopen("DUMMY.FIL", "r");    /* read a character from the file */    fgetc(stream);    /* check for EOF */    if (feof(stream))       printf("We have reached end-of-file\n");    /* close the file */    fclose(stream);    return 0; }     

函数名: ferror

功 能: 检测流上的错误

用 法: int ferror(FILE *stream);

程序例:

#include <stdio.h> int main(void) {    FILE *stream;    /* open a file for writing */    stream = fopen("DUMMY.FIL", "w");    /* force an error condition by attempting to read */    (void) getc(stream);    if (ferror(stream))  /* test for an error on the stream */    {       /* display an error message */       printf("Error reading from DUMMY.FIL\n");       /* reset the error and EOF indicators */       clearerr(stream);    }    fclose(stream);    return 0; }       

函数名: fflush

功 能: 清除一个流

用 法: int fflush(FILE *stream);

程序例:

#include <string.h> #include <stdio.h> #include <conio.h> #include <io.h> void flush(FILE *stream); int main(void) {    FILE *stream;    char msg[] = "This is a test";    /* create a file */    stream = fopen("DUMMY.FIL", "w");    /* write some data to the file */    fwrite(msg, strlen(msg), 1, stream);    clrscr();    printf("Press any key to flush\    DUMMY.FIL:");    getch();    /* flush the data to DUMMY.FIL without\       closing it */    flush(stream);    printf("\nFile was flushed, Press any key\    to quit:");    getch();    return 0; } void flush(FILE *stream) {      int duphandle;      /* flush the stream's internal buffer */      fflush(stream);      /* make a duplicate file handle */      duphandle = dup(fileno(stream));      /* close the duplicate handle to flush\         the DOS buffer */      close(duphandle); }       

函数名: fgetc

功 能: 从流中读取字符

用 法: int fgetc(FILE *stream);

程序例:

#include <string.h> #include <stdio.h> #include <conio.h> int main(void) {    FILE *stream;    char string[] = "This is a test";    char ch;    /* open a file for update */    stream = fopen("DUMMY.FIL", "w+");    /* write a string into the file */    fwrite(string, strlen(string), 1, stream);    /* seek to the beginning of the file */    fseek(stream, 0, SEEK_SET);    do    {       /* read a char from the file */       ch = fgetc(stream);       /* display the character */       putch(ch);    } while (ch != EOF);    fclose(stream);    return 0; }       

函数名: fgetchar

功 能: 从流中读取字符

用 法: int fgetchar(void);

程序例:

#include <stdio.h> int main(void) {    char ch;    /* prompt the user for input */    printf("Enter a character followed by \    <Enter>: ");    /* read the character from stdin */    ch = fgetchar();    /* display what was read */    printf("The character read is: '%c'\n",           ch);    return 0; }       

函数名: fgetpos

功 能: 取得当前文件的句柄

用 法: int fgetpos(FILE *stream);

程序例:

#include <string.h> #include <stdio.h> int main(void) {    FILE *stream;    char string[] = "This is a test";    fpos_t filepos;    /* open a file for update */    stream = fopen("DUMMY.FIL", "w+");    /* write a string into the file */    fwrite(string, strlen(string), 1, stream);    /* report the file pointer position */    fgetpos(stream, &filepos);    printf("The file pointer is at byte\           %ld\n", filepos);    fclose(stream);    return 0; }       

函数名: fgets

功 能: 从流中读取一字符串

用 法: char *fgets(char *string, int n, FILE *stream);

程序例:

#include <string.h> #include <stdio.h> int main(void) {    FILE *stream;    char string[] = "This is a test";    char msg[20];    /* open a file for update */    stream = fopen("DUMMY.FIL", "w+");    /* write a string into the file */    fwrite(string, strlen(string), 1, stream);    /* seek to the start of the file */    fseek(stream, 0, SEEK_SET);    /* read a string from the file */    fgets(msg, strlen(string)+1, stream);    /* display the string */    printf("%s", msg);    fclose(stream);    return 0; }       

函数名: filelength

功 能: 取文件长度字节数

用 法: long filelength(int handle);

程序例:

#include <string.h> #include <stdio.h> #include <fcntl.h> #include <io.h> int main(void) {    int handle;    char buf[11] = "0123456789";    /* create a file containing 10 bytes */    handle = open("DUMMY.FIL", O_CREAT);    write(handle, buf, strlen(buf));    /* display the size of the file */    printf("file length in bytes: %ld\n",    filelength(handle));    /* close the file */    close(handle);    return 0; }     

函数名: fillellipse

功 能: 画出并填充一椭圆

用 法: void far fillellipse(int x, int y, int xradius, int yradius);

程序例:

#include <graphics.h> #include <conio.h> int main(void) {    int gdriver = DETECT, gmode;    int xcenter, ycenter, i;    initgraph(&gdriver,&gmode,"");    xcenter = getmaxx() / 2;    ycenter = getmaxy() / 2;    for (i=0; i<13; i++)    {       setfillstyle(i,WHITE);       fillellipse(xcenter,ycenter,100,50);       getch();    }    closegraph();    return 0; }       

函数名: fillpoly

功 能: 画并填充一个多边形

用 法: void far fillpoly(int numpoints, int far *polypoints);

程序例:

#include <graphics.h> #include <stdlib.h> #include <stdio.h> #include <conio.h> int main(void) {    /* request auto detection */    int gdriver = DETECT, gmode, errorcode;    int i, maxx, maxy;    /* our polygon array */    int poly[8];    /* initialize graphics, local variables */    initgraph(&gdriver, &gmode, "");    /* read result of initialization */    errorcode = graphresult();    if (errorcode != grOk)    /* an error occurred */    {       printf("Graphics error: %s\n",              grapherrormsg(errorcode));       printf("Press any key to halt:");       getch();       exit(1);       /* terminate with an error code */    }    maxx = getmaxx();    maxy = getmaxy();    poly[0] = 20;        /* 1st vertext */    poly[1] = maxy / 2;    poly[2] = maxx - 20; /* 2nd */    poly[3] = 20;    poly[4] = maxx - 50; /* 3rd */    poly[5] = maxy - 20;    /*       4th vertex. fillpoly automatically       closes the polygon.    */    poly[6] = maxx / 2;    poly[7] = maxy / 2;    /* loop through the fill patterns */    for (i=EMPTY_FILL; i<USER_FILL; i++)    {       /* set fill pattern */       setfillstyle(i, getmaxcolor());       /* draw a filled polygon */       fillpoly(4, poly);       getch();    }    /* clean up */    closegraph();    return 0; }       

函数名: findfirst, findnext

功 能: 搜索磁盘目录; 取得下一个匹配的findfirst模式的文件

用 法: int findfirst(char *pathname, struct ffblk *ffblk, int attrib);

 int findnext(struct ffblk *ffblk); 

程序例:

/* findnext example */ #include <stdio.h> #include <dir.h> int main(void) {    struct ffblk ffblk;    int done;    printf("Directory listing of *.*\n");    done = findfirst("*.*",&ffblk,0);    while (!done)    {       printf("  %s\n", ffblk.ff_name);       done = findnext(&ffblk);    }    return 0; }       

函数名: floodfill

功 能: 填充一个有界区域

用 法: void far floodfill(int x, int y, int border);

程序例:

#include <graphics.h> #include <stdlib.h> #include <stdio.h> #include <conio.h> int main(void) {    /* request auto detection */    int gdriver = DETECT, gmode, errorcode;    int maxx, maxy;    /* initialize graphics, local variables */    initgraph(&gdriver, &gmode, "");    /* read result of initialization */    errorcode = graphresult();    if (errorcode != grOk)    /* an error occurred */    {       printf("Graphics error: %s\n",              grapherrormsg(errorcode));       printf("Press any key to halt:");       getch();       exit(1);       /* terminate with an error code */    }    maxx = getmaxx();    maxy = getmaxy();    /* select drawing color */    setcolor(getmaxcolor());    /* select fill color */    setfillstyle(SOLID_FILL, getmaxcolor());    /* draw a border around the screen */    rectangle(0, 0, maxx, maxy);    /* draw some circles */    circle(maxx / 3, maxy /2, 50);    circle(maxx / 2, 20, 100);    circle(maxx-20, maxy-50, 75);    circle(20, maxy-20, 25);    /* wait for a key */    getch();    /* fill in bounded region */    floodfill(2, 2, getmaxcolor());    /* clean up */    getch();    closegraph();    return 0; }       

函数名: floor

功 能: 向下舍入

用 法: double floor(double x);

程序例:

#include <stdio.h> #include <math.h> int main(void) {    double number = 123.54;    double down, up;    down = floor(number);    up = ceil(number);    printf("original number     %10.2lf\n",           number);    printf("number rounded down %10.2lf\n",           down);    printf("number rounded up   %10.2lf\n",           up);    return 0; }       

函数名: flushall

功 能: 清除所有缓冲区

用 法: int flushall(void);

程序例:

#include <stdio.h> int main(void) {    FILE *stream;    /* create a file */    stream = fopen("DUMMY.FIL", "w");    /* flush all open streams */    printf("%d streams were flushed.\n",    flushall());    /* close the file */    fclose(stream);    return 0; }       

函数名: fmod

功 能: 计算x对y的模, 即x/y的余数

用 法: double fmod(double x, double y);

程序例:

#include <stdio.h> #include <math.h> int main(void) {    double x = 5.0, y = 2.0;    double result;    result = fmod(x,y);    printf("The remainder of (%lf / %lf) is \           %lf\n", x, y, result);    return 0; }       

函数名: fnmerge

功 能: 建立新文件名

用 法: void fnerge(char *path, char *drive, char *dir);

程序例:

#include <string.h> #include <stdio.h> #include <dir.h>   int main(void) {     char s[MAXPATH];     char drive[MAXDRIVE];     char dir[MAXDIR];     char file[MAXFILE];     char ext[MAXEXT];     getcwd(s,MAXPATH);              /* get the current working directory */     strcat(s,"\\");                  /* append on a trailing \ character */     fnsplit(s,drive,dir,file,ext); /* split the string to separate elems */     strcpy(file,"DATA");     strcpy(ext,".TXT");     fnmerge(s,drive,dir,file,ext);   /* merge everything into one string */     puts(s);                                 /* display resulting string */     return 0; }       

函数名: fopen

功 能: 打开一个流

用 法: FILE *fopen(char *filename, char *type);

程序例:

#include <stdlib.h> #include <stdio.h> #include <dir.h> int main(void) {     char *s;     char drive[MAXDRIVE];     char dir[MAXDIR];     char file[MAXFILE];     char ext[MAXEXT];     int flags;     s=getenv("COMSPEC"); /* get the comspec environment parameter */     flags=fnsplit(s,drive,dir,file,ext);     printf("Command processor info:\n");     if(flags & DRIVE)        printf("\tdrive: %s\n",drive);     if(flags & DIRECTORY)        printf("\tdirectory: %s\n",dir);     if(flags & FILENAME)        printf("\tfile: %s\n",file);     if(flags & EXTENSION)        printf("\textension: %s\n",ext);     return 0; }   

函数名: fprintf

功 能: 传送格式化输出到一个流中

用 法: int fprintf(FILE *stream, char *format[, argument,...]);

程序例:

/* Program to create backup of the    AUTOEXEC.BAT file */ #include <stdio.h> int main(void) {    FILE *in, *out;    if ((in = fopen("\\AUTOEXEC.BAT", "rt"))        == NULL)    {       fprintf(stderr, "Cannot open input \        file.\n");       return 1;    }    if ((out = fopen("\\AUTOEXEC.BAK", "wt"))        == NULL)    {       fprintf(stderr, "Cannot open output \        file.\n");       return 1;    }    while (!feof(in))       fputc(fgetc(in), out);    fclose(in);    fclose(out);    return 0; }       

函数名: FP_OFF

功 能: 获取远地址偏移量

用 法: unsigned FP_OFF(void far *farptr);

程序例:

/* FP_OFF */ #include <dos.h> #include <stdio.h> int main(void) {    char *str = "fpoff.c";    printf("The offset of this file in memory\           is: %Fp\n", FP_OFF(str));    return 0; }     

函数名: FP_SEG

功 能: 获取远地址段值

用 法: unsigned FP_SEG(void far *farptr);

程序例:

/* FP_SEG */ #include <dos.h> #include <stdio.h> int main(void) {    char *filename = "fpseg.c";    printf("The offset of this file in memory\    is: %Fp\n", FP_SEG(filename));    return(0); }       

函数名: fputc

功 能: 送一个字符到一个流中

用 法: int fputc(int ch, FILE *stream);

程序例:

#include <stdio.h> int main(void) {    char msg[] = "Hello world";    int i = 0;    while (msg[i])    {       fputc(msg[i], stdout);       i++;    }    return 0; }       

函数名: fputchar

功 能: 送一个字符到标准输出流(stdout)中

用 法: int fputchar(char ch);

程序例:

#include <stdio.h> int main(void) {    char msg[] = "This is a test";    int i = 0;    while (msg[i])    {       fputchar(msg[i]);       i++;    }    return 0; }       

函数名: fputs

功 能: 送一个字符到一个流中

用 法: int fputs(char *string, FILE *stream);

程序例:

#include <stdio.h> int main(void) {    /* write a string to standard output */    fputs("Hello world\n", stdout);    return 0; }       

函数名: fread

功 能: 从一个流中读数据

用 法: int fread(void *ptr, int size, int nitems, FILE *stream);

程序例:

#include <string.h> #include <stdio.h> int main(void) {    FILE *stream;    char msg[] = "this is a test";    char buf[20];    if ((stream = fopen("DUMMY.FIL", "w+"))        == NULL)    {       fprintf(stderr,               "Cannot open output file.\n");       return 1;    }    /* write some data to the file */    fwrite(msg, strlen(msg)+1, 1, stream);    /* seek to the beginning of the file */    fseek(stream, SEEK_SET, 0);    /* read the data and display it */    fread(buf, strlen(msg)+1, 1, stream);    printf("%s\n", buf);    fclose(stream);    return 0; }     

函数名: free

功 能: 释放已分配的块

用 法: void free(void *ptr);

程序例:

#include <string.h> #include <stdio.h> #include <alloc.h> int main(void) {    char *str;    /* allocate memory for string */    str = malloc(10);    /* copy "Hello" to string */    strcpy(str, "Hello");    /* display string */    printf("String is %s\n", str);    /* free memory */    free(str);    return 0; }   

函数名: freemem

功 能: 释放先前分配的DOS内存块

用 法: int freemem(unsigned seg);

程序例:

#include <dos.h> #include <alloc.h> #include <stdio.h> int main(void) {    unsigned int size, segp;    int stat;    size = 64; /* (64 x 16) = 1024 bytes */    stat = allocmem(size, &segp);    if (stat < 0)       printf("Allocated memory at segment:\       %x\n", segp);    else       printf("Failed: maximum number of\       paragraphs available is %u\n",       stat);    freemem(segp);    return 0; }     

函数名: freopen

功 能: 替换一个流

用 法: FILE *freopen(char *filename, char *type, FILE *stream);

程序例:

#include <stdio.h> int main(void) {    /* redirect standard output to a file */    if (freopen("OUTPUT.FIL", "w", stdout)        == NULL)       fprintf(stderr, "error redirecting\               stdout\n");    /* this output will go to a file */    printf("This will go into a file.");    /* close the standard output stream */    fclose(stdout);    return 0; }       

函数名: frexp

功 能: 把一个双精度数分解为尾数的指数

用 法: double frexp(double value, int *eptr);

程序例:

#include <math.h> #include <stdio.h> int main(void) {    double mantissa, number;    int exponent;    number = 8.0;    mantissa = frexp(number, &exponent);    printf("The number %lf is ", number);    printf("%lf times two to the ", mantissa);    printf("power of %d\n", exponent);    return 0; }     

函数名: fscanf

功 能: 从一个流中执行格式化输入

用 法: int fscanf(FILE *stream, char *format[,argument...]);

程序例:

#include <stdlib.h> #include <stdio.h> int main(void) {    int i;    printf("Input an integer: ");    /* read an integer from the       standard input stream */    if (fscanf(stdin, "%d", &i))       printf("The integer read was: %i\n",              i);    else    {       fprintf(stderr, "Error reading an \               integer from stdin.\n");       exit(1);    }    return 0; }       

函数名: fseek

功 能: 重定位流上的文件指针

用 法: int fseek(FILE *stream, long offset, int fromwhere);

程序例:

#include <stdio.h> long filesize(FILE *stream); int main(void) {    FILE *stream;    stream = fopen("MYFILE.TXT", "w+");    fprintf(stream, "This is a test");    printf("Filesize of MYFILE.TXT is %ld bytes\n", filesize(stream));    fclose(stream);    return 0; } long filesize(FILE *stream) {    long curpos, length;    curpos = ftell(stream);    fseek(stream, 0L, SEEK_END);    length = ftell(stream);    fseek(stream, curpos, SEEK_SET);    return length; }           

函数名: fsetpos

功 能: 定位流上的文件指针

用 法: int fsetpos(FILE *stream, const fpos_t *pos);

程序例:

#include <stdlib.h> #include <stdio.h> void showpos(FILE *stream); int main(void) {    FILE *stream;    fpos_t filepos;    /* open a file for update */    stream = fopen("DUMMY.FIL", "w+");    /* save the file pointer position */    fgetpos(stream, &filepos);    /* write some data to the file */    fprintf(stream, "This is a test");    /* show the current file position */    showpos(stream);    /* set a new file position, display it */    if (fsetpos(stream, &filepos) == 0)      showpos(stream);    else    {       fprintf(stderr, "Error setting file \        pointer.\n");       exit(1);    }    /* close the file */    fclose(stream);    return 0; } void showpos(FILE *stream) {    fpos_t pos;    /* display the current file pointer       position of a stream */    fgetpos(stream, &pos);    printf("File position: %ld\n", pos); }   

函数名: fstat

功 能: 获取打开文件信息

用 法: int fstat(char *handle, struct stat *buff);

程序例:

#include <sys\stat.h> #include <stdio.h> #include <time.h> int main(void) {    struct stat statbuf;    FILE *stream;    /* open a file for update */    if ((stream = fopen("DUMMY.FIL", "w+"))        == NULL)    {       fprintf(stderr, "Cannot open output \               file.\n");       return(1);    }    fprintf(stream, "This is a test");    fflush(stream);    /* get information about the file */    fstat(fileno(stream), &statbuf);    fclose(stream);    /* display the information returned */    if (statbuf.st_mode & S_IFCHR)       printf("Handle refers to a device.\n");    if (statbuf.st_mode & S_IFREG)       printf("Handle refers to an ordinary \              file.\n");    if (statbuf.st_mode & S_IREAD)       printf("User has read permission on \              file.\n");    if (statbuf.st_mode & S_IWRITE)       printf("User has write permission on \               file.\n");    printf("Drive letter of file: %c\n",    'A'+statbuf.st_dev);    printf("Size of file in bytes: %ld\n",    statbuf.st_size);    printf("Time file last opened: %s\n",    ctime(&statbuf.st_ctime));    return 0; }       

函数名: ftell

功 能: 返回当前文件指针

用 法: long ftell(FILE *stream);

程序例:

#include <stdio.h> int main(void) {    FILE *stream;    stream = fopen("MYFILE.TXT", "w+");    fprintf(stream, "This is a test");    printf("The file pointer is at byte \           %ld\n", ftell(stream));    fclose(stream);    return 0; }       

函数名: fwrite

功 能: 写内容到流中

用 法: int fwrite(void *ptr, int size, int nitems, FILE *stream);

程序例:

#include <stdio.h> struct mystruct {   int i;   char ch; }; int main(void) {    FILE *stream;    struct mystruct s;    if ((stream = fopen("TEST.$$$", "wb")) == NULL) /* open file TEST.$$$ */    {       fprintf(stderr, "Cannot open output file.\n");       return 1;    }    s.i = 0;    s.ch = 'A';    fwrite(&s, sizeof(s), 1, stream); /* write struct s to file */    fclose(stream); /* close file */    return 0; }     

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