C SIMPLE Temperature converter / Celsius to Fahrenheit UNKNOWN errors & output - c

Question

I just started programming in C a few days ago and have a few questions:
The following program converts Celsius into Fahrenheit and vice versa. I am getting a Segmentation fault error.
#include<stdio.h>
#include <string.h>
#include<stdlib.h>
float c2f(float);
float f2c(float);
float Fahrenheit,Celsius;
int main(int argc, char *argv[])
{
/**
* Check for the expected number of arguments (3)
* (0) program name
* (1) flag
* (2) temperature
*/
if (argc!=3)
printf("Incorrect number of arguments");
if (!strcmp(argv[1], "->f"))
{
// convert the string into a floating number
char *check;
float Celsius = strtod(argv[2], &check);
// process from celsius to fahrenheit
Fahrenheit = c2f(Celsius);
printf("%5.2f°C = %5.2f°F",Celsius, Fahrenheit);
}
else if (!strcmp(argv[1], "->c"))
{
// convert the string into a floating number
char *check;
float Fahrenheit = strtod(argv[2], &check);
// process from fahrenheit to celsius
Celsius = f2c(Fahrenheit);
printf("%5.2f°F = %5.2f°C", Fahrenheit, Celsius);
}
else
printf("Invalid flag\n");
} // main
float c2f(float c)
{
return 32 + (c * (180.0 / 100.0));
}
float f2c(float f)
{
return (100.0 / 180.0) * (f - 32);
}
Also, I want my output to be like this:
**> TemperatureConverter ->f 10.0
10.00°C = 50.00°F**
This should convert 10C into F.
For F to C, the output should be:
TemperatureConverter ->c 50.0
50.00°F = 10C**

Answer 1

the error is
if (!strcmp(argv[1], "->f")
it's missing a final parenthesis, should be
if (!strcmp(argv[1], "->f"))
and you made the same mistake twice. 1 paren for strcmp(), 1 for if()
you should include string.h. Also, you should put you functions f2c and c2f before main.
also you wrote
prinf
try with a t before the f
printf
finally you need
exit(0);
after the first if. eg
if (argc!=3)
{
printf("Incorrect number of arguments");
exit(0);
}
otherwise the rest of the program runs and you get seg fault. Welcome to programming.

Answer 2

Slight nitpicking:
float c2f(float);
float f2c(float);
While it's technically correct, remember to include the variable name as well in your function declarations. It makes it easier to read.
As an example
float c2f(float c);

Answer 3

I used this code :
/* Declare Initial library for functions */
#include<stdio.h>
#include<conio.h>
/* Main function*/
void main()
{
/* data type(float),variable(c,f)*/
float c, f;
/* printf function from stdio.h library , for printing level*/
printf("Enter temp. in Celsius: ");
/* scanf for inserting data in variable*/
scanf("%f",&c);
/* Fahrenheit rules*/
f = c * 9/5 + 32;
/* Result will display in this line */
printf("Temp. in Fahrenheit: %f",f);
/* getch function from conio.h library, used to write a character to screen*/
getch();
}