fopen

 

C

语言

类型的支持

动态内存管理

错误处理

程序实用工具

日期和时间工具

字符串库

算法

数值计算

输入/输出的支持

本地化的支持

线程的支持 （C11）

原子操作 （C11）

 

File input/output

功能 Original: Functions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
文件访问 Original: File access The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
fopen freopen fclose fflush	fwide setbuf setvbuf
直接输入/输出 Original: Direct input/output The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
fread
fwrite
未格式化的输入/输出 Original: Unformatted input/output The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
fgetc fgets fputc fputs getchar gets putchar puts ungetc	fgetwc fgetws fputwc fputws getwchar putwchar ungetwc
格式化输入/输出 Original: Formatted input/output The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
scanf fscanf sscanf vscanf vfscanf vsscanf （C99） （C99） （C99） printf fprintf sprintf snprintf （C99） vprintf vfprintf vsprintf vsnprintf （C99）	wscanf fwscanf swscanf vwscanf vfwscanf vswscanf （C99） （C99） （C99） wprintf fwprintf swprintf vwprintf vfwprintf vswprintf
文件定位 Original: File positioning The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
ftell
fgetpos
fseek
fsetpos
rewind
错误处理 Original: Error handling The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
clearerr
feof
ferror
perror
对文件的操作 Original: Operations on files The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
remove
rename
tmpfile
tmpnam

 

Defined in header <stdio.h>
FILE *fopen( const char *filename, const char *mode );

表示filename打开一个文件，并返回一个文件流关联的文件。 mode用于确定文件访问模式.

Original:

Opens a file indicated by filename and returns a file stream associated with that file. mode is used to determine the file access mode.

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You can help to correct and verify the translation. Click here for instructions.

参数

filename	-	文件名称相关联的文件流 Original: file name to associate the file stream to The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
mode	-	空字符结尾的字符串，确定文件的访问模式 File access mode string Meaning Explanation Action if file already exists Action if file does not exist "r" read Open a file for reading read from start failure to open "w" write Create a file for writing destroy contents create new "a" append Append to a file write to end create new "r+" read extended Open a file for read/write read from start error "w+" write extended Create a file for read/write destroy contents create new "a+" append extended Open a file for read/write write to end create new File access mode flag "b" can optionally be specified to open a file in binary mode. This flag has effect only on Windows systems. On the append file access modes, data is written to the end of the file regardless of the current position of the file position indicator. Original: null-terminated character string determining file access mode File access mode string Meaning Explanation Action if file already exists Action if file does not exist "r" read Open a file for reading read from start failure to open "w" write Create a file for writing destroy contents create new "a" append Append to a file write to end create new "r+" read extended Open a file for read/write read from start error "w+" write extended Create a file for read/write destroy contents create new "a+" append extended Open a file for read/write write to end create new File access mode flag "b" can optionally be specified to open a file in binary mode. This flag has effect only on Windows systems. On the append file access modes, data is written to the end of the file regardless of the current position of the file position indicator. The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

返回值

打开的文件流上的成功，失败的NULL上

Original:

Opened file stream on success, NULL on failure

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示例

#include <stdio.h>
int main()
{
    FILE *fp;
    fp = fopen("test.txt", "r");
    if (fp != NULL){
    	printf("succeed!");
        fclose(fp);
    }
    else
    	printf("fail!");
 
    return 0;
}

另请参阅

fclose	关闭一个文件 Original: closes a file The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （函数）
fflush	实际的文件同步输出流 Original: synchronizes an output stream with the actual file The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （函数）
freopen	打开一个现有的流用不同的名称 Original: open an existing stream with a different name The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （函数）
C++ documentation for fopen