Question

I’m a student and this is my first exposure to bash scripting, besides messing with a simple Makefile for c.

#!/usr/bin/sh
gcc -g -std=c99 -Wall -c field.c 
gcc -g -std=c99 -Wall -c testField.c 
gcc -g field.o testField.o -o testField 
#testField get 0xa 0 1 > PA1output.txt 
#testField get 0xaa 0 3 >> PA1output.txt

is my script.I want to compile field.c and testField.c into the executable testField.
No matter if I leave the last 2 lines commented out or not, they linux terminal hangs and after 10 seconds of nothing happening I press ctrl+c to stop it. Ultimately I want to redirect output to PA1output.txt, then concatenate things on the end of the file, but I want to rewrite the file contents each time.

As far as I understand it, > rewrites the contents of the specified file, and >> concatenates onto the end.

This is not my homework, I want to automate testing of other homework I have. ‘testField get 0xaa 0 3 are arguments into my c program.’

I tried Bash script hangs
but that didn’t answer my question totally.

My script is called ‘as’ to make it easy to type.

Why does the terminal hang and how do I get the script to do what I described above?

Thanks.

Answer 1

Your system has another program called ‘as’ which is an assembler. You are likely running this rather than your script, and it hangs because the assembler is waiting for input from your terminal.

If you insist on keeping the name, you should run your script with a full or partial pathname (like ‘./as’) so that the correct program is run.

You will probably find that your script will not run without the ‘#’ at the beginning of your first line. However, another way to run your script is ‘sh ./as’ from the command line, which does not depend on having the #! line.