使用BASH的文本檔案中的輸入重定向以用作C程式中的資料

我需要收集寫入文本檔案的資料并使用 bash shell，它允許文本檔案的每一行在我的 c 程式中用作單獨的資料點。對于更多的背景關系，我的程式正在為我的 input.txt 檔案中的多行獲取一組坐標（x，y）。之后，它會根據它所在的點找到最近和最遠的點。

例如 input.txt 有以下幾行：

    input1 3.2 9.3
    input2 5.7 13.6
    input3 18.4 12.2

我還沒有找到如何在 bash 上執行此操作。我撰寫了以下程式來做一些非常相似但不是動態使用 bash 重定向的事情。

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

struct coordinates{
    //The label of the coordinates
    char coordinateName[32];
    //The x and y coordinates
    float xCoord;
    float yCoord;

} coordinate;

//Function to calculate distance from another point
float distance(char p1[32], char p2[32], float x1, float x2, float y1, float y2){
    float c;

    c = sqrt( pow((x1-x2),2)   pow((y1-y2),2) );

    printf("\nDistance between %s and %s is: %f", p1, p2, c);
    return c;
}

int main (int argc, char *argv[]) {
    // Get the number of inputs being taken in from the user via command line
    int ENTRIES = atoi(argv[1]);
    // Declare a struct object
    struct coordinates myCoordinates[ENTRIES];

    for(int i = 0; i<ENTRIES; i  ){
        // Enter the coordinate name
        printf("Enter a Coordinate name: ");
        scanf("%s", &*myCoordinates[i].coordinateName);
        // Ask for x coordinate
        printf("Enter a Coordinate value for x: ");
        scanf("%f", &myCoordinates[i].xCoord);
        // Ask for y coordinate
        printf("Enter a Coordinate value for y: ");
        scanf("%f", &myCoordinates[i].yCoord);
    }
    printf("\n");

    //define closest and furthest points
    float closestPoints = INFINITY, furthestPoints = 0.0;
    int closestPoint1, closestPoint2;
    int furthestPoint1, furthestPoint2;
    //define calculation variable to check against closest and furthest point
    float calculation;

    for(int i = 0; i <= ENTRIES-1; i  ){
        for (int j = 0; j <= ENTRIES-1; j  ) {

            char *p1,*p2;
            float x1,x2,y1,y2;

            p1 = myCoordinates[i].coordinateName;
            x1 = myCoordinates[i].xCoord;
            y1 = myCoordinates[i].yCoord;
            p2 = myCoordinates[j].coordinateName;
            x2 = myCoordinates[j].xCoord;
            y2 = myCoordinates[j].yCoord;

            //if coord1 is equal to coord2
            if(i==j){
                continue;
            }
            else{
                calculation = distance(p1, p2, x1, x2, y1, y2);

                if (calculation < closestPoints){
                    closestPoint1 = i;
                    closestPoint2 = j;
                    closestPoints = calculation;
                }
                if (calculation > furthestPoints){
                    furthestPoint1 = i;
                    furthestPoint2 = j;
                    furthestPoints = calculation;
                }
            }
        }
    }

    printf("\nClosest points from one another is point %s and point %s with a distance of %f", myCoordinates[closestPoint1].coordinateName, myCoordinates[closestPoint2].coordinateName, closestPoints);
    printf("\nFurthest points from one another is point %s and point %s with a distance of %f", myCoordinates[furthestPoint1].coordinateName, myCoordinates[furthestPoint2].coordinateName, furthestPoints);
}

任何對此的見解或資料將不勝感激。謝謝

uj5u.com熱心網友回復：

假設 C 代碼被編譯為可執行檔案a.out，請您嘗試 bash 代碼：

#!/bin/bash
./a.out $(wc -l < input.txt) < input.txt > output,txt

• $(wc -l < input.txt)計算輸入檔案的行數并a.out作為第一個引數傳遞給。
• 被input.txt重定向到 的標準輸入，a.out 輸出被重定向到output.txt作為新檔案創建的 。

C 代碼無需修改即可作業，但可以進行改進，例如洗掉提示。

標籤：C 重击

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