C语言文件 *** 作，要读取一个txt文件内容，应该怎么做？

//data.txt文件内容如下\x0d\x0a\x0d\x0a1个猪\x0d\x0a2个猪\x0d\x0a3个猪\x0d\x0a4个猪\x0d\x0a5个猪\x0d\x0a6个猪\x0d\x0a7个猪\x0d\x0a8个猪\x0d\x0a\x0d\x0a//运行结果一\x0d\x0athe 8 line :8 个 猪\x0d\x0a\x0d\x0aPress any key to continue \x0d\x0a//运行结果二\x0d\x0aout of range!\x0d\x0aPress any key to continue \x0d\x0a\x0d\x0a//代码如下\x0d\x0a#include \x0d\x0a#include \x0d\x0a#include \x0d\x0amain(void)\x0d\x0a{\x0d\x0aint lid,cnt=0,flag=0\x0d\x0achar buf[100]="\0"\x0d\x0aFILE *fp\x0d\x0a\x0d\x0asrand((unsigned)time(NULL))\x0d\x0afp=fopen("data.txt","r")\x0d\x0alid= rand()%10+1\x0d\x0awhile (fgets(buf,99,fp)!=NULL)\x0d\x0a{\x0d\x0aif(cnt==lid)\x0d\x0a{\x0d\x0aprintf("the %d line :%s\n",lid+1,buf)\x0d\x0aflag=1\x0d\x0abreak\x0d\x0a}\x0d\x0acnt++\x0d\x0a}\x0d\x0aif (flag==0)\x0d\x0a{\x0d\x0aprintf("out of range!\n")\x0d\x0a}\x0d\x0a}

C语言可以使用fopen（）函数读取txt文本里。

示例：

#include <stdio.h>

FILE *stream, *stream2

void main( void )

{

int numclosed

/* Open for read (will fail if file "data" does not exist) */

if( (stream  = fopen( "data", "r" )) == NULL )

printf( "The file 'data' was not opened\n" )

else

printf( "The file 'data' was opened\n" )

/* Open for write */

if( (stream2 = fopen( "data2", "w+" )) == NULL )

printf( "The file 'data2' was not opened\n" )

else

printf( "The file 'data2' was opened\n" )

/* Close stream */

if(fclose( stream2 ))

printf( "The file 'data2' was not closed\n" )

/* All other files are closed: */

numclosed = _fcloseall( )

printf( "Number of files closed by _fcloseall: %u\n", numclosed )

}

扩展资料

使用fgetc函数

#include <stdio.h>

#include <stdlib.h>

void main( void )

{

FILE *stream

char buffer[81]

int  i, ch

/* Open file to read line from: */

if( (stream = fopen( "fgetc.c", "r" )) == NULL )

exit( 0 )

/* Read in first 80 characters and place them in "buffer": */

ch = fgetc( stream )

for( i=0(i <80 ) &&( feof( stream ) == 0 )i++ )

{

buffer[i] = (char)ch

ch = fgetc( stream )

}

/* Add null to end string */

buffer[i] = '\0'

printf( "%s\n", buffer )

fclose( stream )

}

一、编程思路。

1 以文本方式打开文件。

2 循环用fscanf格式化输入数据到数组。

3 判断fscanf的返回值，如果显示到达文件结尾，退出输入。

4 关闭文件。

5 使用数据。

二、代码实现。

设定文件名为in.txt, 存有一系列整型数据，以空格或换行分隔。

代码可以写作：

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#include <stdio.h>

int main()

{

int v[100]//开一个足够大的数组。

int i = 0, j

FILE *fp//文件指针

fp = fopen("in.txt", "r")//以文本方式打开文件。

if(fp == NULL) //打开文件出错。

return -1

while(fscanf(fp, "%d", &v[i]) != EOF) //读取数据到数组，直到文件结尾(返回EOF)

i++

fclose(fp)//关闭文件

for(j = 0j <ij ++)//循环输出数组元素。

{

printf("%d ", v[j])

}

return 0

}

当文件内容为：

1 35 6 8 9 9

10 123 34

76 54 98

程序输出：

1 35 6 8 9 9 10 123 34 76 54 98

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