CODEWITHSUNDEEP
clinuxdebugginggdb
user1618033988749895
user1618033988749895

Reputation: 49

Getting an error that states "printf.c: No such file or directory" while using GDB on a very basic C program for temperature conversion

(gdb) break main
Breakpoint 1 at 0x722: file homework1.c, line 4.
(gdb) run
Starting program: /home/aj_the_kid/ECE_373/homework1 
Breakpoint 1, main () at homework1.c:4
4   {
(gdb) step
8     printf("Enter the temperature (for conversion) in Fahrenheit:  ");
(gdb) step
__printf (
    format=0x555555554838 "Enter the temperature (for conversion) in Fahrenheit:  ") at printf.c:28
28  printf.c: No such file or directory.
(gdb) bt
 #0  __printf (
    format=0x555555554838 "Enter the temperature (for conversion) in Fahrenheit:  ") at printf.c:28
 #1  0x0000555555554742 in main () at homework1.c:8
(gdb) next
32  in printf.c
(gdb) next
33  in printf.c
(gdb) step
_IO_vfprintf_internal (s=0x7ffff7dd0760 <_IO_2_1_stdout_>, 
    format=0x555555554838 "Enter the temperature (for conversion) in Fahrenheit:  ", ap=ap@entry=0x7fffffffde20) at vfprintf.c:1244
1244    vfprintf.c: No such file or directory.
(gdb) step
1275    in vfprintf.c

#include <stdio.h>

int main()
{
  float temp_F, temp_C;

  // Prompt user for input (i.e. temp in Fahrenheit)
  printf("Enter the temperature (for conversion) in Fahrenheit:  ");
  scanf("%f\n", &temp_F);

  // Convert F to C
  temp_C = (temp_F - 32) * (5/9);
  printf("The temperature in Celsius is: %.2f\n", temp_C);

  return 0;

}

But I am still getting the issue where it requires me to input the degrees in Fahrenheit again in an empty line like it didnt capture the user input the first time

Terminal View

aj_the_kid@AJs-Sandbox:~/ECE_373$ rm file1
aj_the_kid@AJs-Sandbox:~/ECE_373$ gcc -g -o file1 file1.c
aj_the_kid@AJs-Sandbox:~/ECE_373$ ./file1
Enter the temperature (for conversion) in Fahrenheit:  32

32
The temperature in celcius is: 0.00
aj_the_kid@AJs-Sandbox:~/ECE_373$

Upvotes: 2

Views: 5483

Answers (1)

user3386109
user3386109

Reputation: 34839

From the comments:

The error message from gdb vfprintf.c: No such file or directory is due to the fact that you're trying to step into a library function for which you don't have source code.

The problem in the calculation is that the division (5/9) is performed as integer division. So the result is 0. This can be fixed by changing to (5.0/9.0)

And the scanf problem is due to the \n at the end of the format string. scanf is a little strange about whitespace. Putting the \n at the end of the format string tells scanf to skip all whitespace until the user types non-whitespace character and presses enter. You can fix it by removing the \n

Upvotes: 2

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