Question

所以我想以命令行的形式运行程序：（./program -f）或（./program -c）取决于我是否要将数字从华氏温度转换为摄氏温度（-f）或摄氏温度转换为华氏温度（-c）。我遇到的问题是我收到错误/警告。我相信我的方法是正确的，但我仍在发展我的技能。

#include <stdio.h>
#include <string.h>

float c2f(float c);
float f2c(float f);

float c2f(float c)
{
  return (9 * c/5 +32);
}

float f2c(float f)
{
  return ((f - 32) * 5/9);
}

int main(int argc, char const *argv[])
{
  char c[3];
  char f[3];

  strcpy(c, "-c");
  strcpy(f, "-f");
  char **p = &argv[1];

  if(strcmp(p, c) == 0)
  {
    float returnc = c2f(atof(argv[2]));
    printf("%f\n", returnc);
  }

  else if(strcmp(p, f) == 0) 
  {
    float returnf = f2c(atof(argv[2]));
    printf("%f\n", returnf);
  }
  else
    printf("Wrong\n");

  return 0;
}

这是我得到的警告：

warning: initialization from incompatible pointer type [-Wincompatible-pointer-types]
char **p = &argv[1];

warning: passing argument 1 of ‘strcmp’ from incompatible pointer type [-Wincompatible-pointer-types]
 if(strcmp(p, c) == 0)

note: expected ‘const char *’ but argument is of type ‘char **’
extern int strcmp (const char *__s1, const char *__s2)

warning: implicit declaration of function ‘atof’ [-Wimplicit-function-declaration]
float returnc = c2f(atof(argv[2]));

warning: passing argument 1 of ‘strcmp’ from incompatible pointer type [-Wincompatible-pointer-types]
else if(strcmp(p, f) == 0)

note: expected ‘const char *’ but argument is of type ‘char **’
extern int strcmp (const char *__s1, const char *__s2)

我运行了我的代码，它只是默认为“Wrong”，这意味着它无法识别-f / -c。

Answer 1

您有分段错误和其他语法错误。您还没有包含库。我调试了你的代码并且它可以工作。

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

float c2f(float c);
float f2c(float f);
int main(int argc, char** argv)
{

    char c[3];
    char f[3];

    strcpy(c, "-c");
    strcpy(f, "-f");
    char* p = argv[1];
    char* s=argv[2];
    float temp=atof(s);
    printf("%s value of p given and value of temperature %f\n",p,temp);
    if (argc<3)
    {
        printf("Please specify two parameters \n");
    }
    else
    {

        if(strcmp(p, c) == 0)
        {

        float returnc = c2f(temp);

        printf("%f\n", returnc);
        } 
        else if(strcmp(p, f) == 0)
        {

        float returnf = f2c(temp);

        printf("%f\n", returnf);
        }
        else
        {
        printf("Specify either -c or -f as parameters\n");
        }
    }
    return 0;
}



float c2f(float c)
{
    return (9 * c)/5 +32;
}

float f2c(float f)
{
    return (f - 32) * 5/9;
}

将来，请提供您收到的错误或警告类型，以便人们更方便地帮助您。

使用命令行

1 个答案: