跳过逗号和列读取 C 输入

Question

我是 C 的新手，我想进行文件读取操作。这里我有 input.txt 其中包含：

(g1,0.95) (g2,0.30) (m3,0.25) (t4,0.12) (s5,0.24)
(m0,0.85) (m1,0.40) (m2,0.25) (m3,0.85) (m4,0.5) (m5,0.10)

现在，我想将 k1、k2、k3 等保存在数组键 [10] 中，将 0.15、0.10、0.05 保存在数组值 [10]

中

有什么办法可以跳过第一个“(”，忽略“,”和“”而不一一指定吗？我试着搜索教程，听说我可以用它阅读前后几个字符，但我想我误导了他们。有人可以告诉我如何实现吗？

#include <stdio.h>
#define HEIGHT 2
#define WIDTH  6

int main(void)
{
     FILE *myfile;
     char nothing[100];
     char leaf[2];
     float value;

     char keys[10];
     float values[10];

     int i;
     int j;
     int counter=0;

     myfile=fopen("input.txt", "r");

     for(i = 0; i < HEIGHT; i++)
     { 
         for (j = 0 ; j < WIDTH; j++)
         { 
             fscanf(myfile,"%1[^(],%s[^,],%4f[^)]",nothing,leaf,value);
             printf("(%s,%f)\n",leaf,value);
             keys[counter]=leaf;
             values[counter]=value;
             counter++;
         }
         printf("\n");
     }

     fclose(myfile);

 }

Answer 1

以下是我的做法：

int main( void )
{
    // open the file
    FILE *fp;
    if ( (fp = fopen("test.txt", "r")) == NULL )
        exit( 1 );

    // declare the arrays
    char keys[10][32];
    float values[10];

    // load them up
    int i;
    for ( i = 0; i < 10; i++ )
        if ( fscanf( fp, " ( %31[^ ,] ,%f )", keys[i], &values[i] ) != 2 )
            break;
    int count = i;

    // print them out
    printf( "%d\n", count );
    for ( i = 0; i < count; i++ )
        printf( "%s %.2f\n", keys[i], values[i] );

    // close the file
    fclose( fp );
}

关键是 scanf 的格式说明符，由 5 个元素组成。请注意，我使用下划线来显示空格

_(_      skips whitespace, matches the opening parenthesis, skips whitespace
%31[^_,] reads at most 31 characters, stopping on a space or a comma
_,       skips whitespace, matches the comma
%f       reads a floating point value
_)       skips whitespace, matches the closing parenthesis

跳过逗号和列读取 C 输入

Reading C Input with skipping commas and columns

c

input

filereader

scanf

file-read