Usage of fscanf function

In the past, when parsing regular files, I either used regular expressions, or stupidly wrote my own program to parse regular files. Today I suddenly discovered that there is a ready-made function in the c library function that can parse regular files, which is the fscanf() function.

##fscanf is located in the header file , and the function prototype is int fscanf(FILE * stream, const char * format, [argument...]); Its function is to read data from the input stream (stream) according to the data format (format) (store it in argument); the difference with fgets is that fscanf ends when it encounters a space or a newline. Note that it also ends when it encounters a space. fgets encounters a space. Not over. (Recommended learning:

C language video tutorial)

fscanf() function (a bit like a regular expression):

Function: Perform formatted input from a stream, fscanf ends when it encounters a space or a newline. Note that it also ends when it encounters a space.

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

int fscanf(file pointer, format string, input list);

Return value: integer, returns the number of parameters read successfully, and returns EOF(-1) on failure.

Example 1:

#include <stdlib.h>
#include <stdio.h>
int main(void)
{
    int i;
    printf("Input an integer:");
    /*从标准输入中读取一个整数*/
    if(fscanf(stdin, "%d",&i))
    printf("The integer read was:%d\n", i);
    else
    {
        fprintf(stderr, "Error reading an integer from stdin.\n");
        exit(1);
    }
    return 0;
}
 
返回EOF如果读取到文件结尾。

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