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bashreadline

Bind interactive command to a key sequence

I'm facing an interesting problem while compiling and executing a C program involving scanf(). I'm using Ubuntu 20.04 LTS with Bash and GCC v10.2.0.

#include <stdio.h>

int main(void)
{
    int decimalInteger;

    printf("Enter a decimal integer value: ");

    scanf("%d", &decimalInteger);

    printf("It can also be written in octal and hexadecimal notations as %o and %x, respectively.\nWith C prefixes, they are %#o (for octal) and %#x/%#X (for hexadecimal).\n", decimalInteger, decimalInteger, decimalInteger, decimalInteger, decimalInteger);

    return 0;
}

When I compile and run this with gcc-10 *.c -std=c11 && ./a.out, it works perfectly fine. Upon pressing the enter key after the input, the cursor moves to the next line.

Output using full command: output using full command

But, when I add bind -x '"\C-h":gcc-10 *.c -std=c11 && ./a.out' to .bashrc and then use Ctrl+H to compile & execute the program, the output looks like this:
this

The console doesn't display the input, and the cursor doesn't move to the next line.

Why is this happening?

Solution

  • This is normal, readline changes terminal settings while reading input. Line editing wouldn't be possible otherwise.

    You need to save original terminal settings into a variable, and restore them before running your program.

    stty_orig=$(stty -g)

my_func() {
  local stty_bkup=$(stty -g)
  stty "$stty_orig"
  # compile and run here
  stty "$stty_bkup"
}

bind -x '"\C-h": my_func'