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fscanf轉換為int和array

[英]fscanf to int and array

我在C程序中收到文件作為參數

每行都有不同數量的整數,如下所示:

1 2 4 5 6
7 8 8 9 10 -1 2 3
12 3 4 -2 2 -3 9 2 4

我想將每行的前2個參數設置為int,將其余所有參數設置為第2行這樣的數組:

int a;
int b;
int c[10];

int a = 7;
int b = 8;
int c = [8,9,10,-1,1,2,3]

我能夠獲得前2個,但無法使它發生在數組中。

任何幫助,將不勝感激

這就是我現在所擁有的:

//get line per line until \n
while (fscanf(fp, "%d %d", a, b) != EOF)
    while (fscanf(fp,"%d [^\n]", c[n]) != EOF)
        n++;

// print each line
for ( int k = 0 ; k < 10; k ++)
    printf("%d %d %d \n", a, b, c[k]);

僅使用fscanf分隔行可能很棘手。 最好用fgets讀一行,然后使用sscanf從那里讀取數字。

同樣, fscanfsscanf返回匹配的項目數。 您不應該檢查EOF。

char line[300];
while (fgets(line, sizeof(line), fp)) {
    int rval = sscanf(line, "%d %d", &a, &b);
    if (rval == 2) {
        int count = 0;
        do {
            rval = sscanf(line, "%d", &c[count++]);
        } while (rval == 1);
    } 
}

讀取C逐行讀取文件,以及如何從c的字符串中提取數字? ,然后您將得到如下結果:

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>

int main(void) {
    FILE * fp;
    char * line = NULL;
    size_t len = 0;
    ssize_t read;

    fp = fopen("input.txt", "r");
    if (fp == NULL)
        return -1;

    while ((read = getline(&line, &len, fp)) != -1) {
        printf("Retrieved line of length %zu:\n", read);
        //printf("%s", line);
        char* p = line;
    int a, b, c[10], counter = -2;
    while (*p) { // While there are more characters to process...
            if ( isdigit(*p) || ( (*p=='-'||*p=='+') && isdigit(*(p+1)) )) {
                // Found a number
                long val = strtol(p, &p, 10); // Read number
                //printf("%ld\n", val); // and print it.
            if(counter == -2)
                a = val;
            else if(counter == -1)
                b = val;
            else if(counter < 10)
                c[counter] = val;
            counter++;
            } else {
                // Otherwise, move on to the next character.
                p++;
            }
    }
    printf("a = %d, b = %d\n", a, b);
    for(int i = 0; i < counter; ++i)
        printf("%d ", c[i]);
    printf("\n");
    }

    fclose(fp);
    if (line)
        free(line);
    return 0;
}

輸出:

Retrieved line of length 10:
a = 1, b = 2
4 5 6 
Retrieved line of length 18:
a = 7, b = 8
8 9 10 -1 2 3 
Retrieved line of length 21:
a = 12, b = 3
4 -2 2 -3 9 2 4 

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