C2110 UNIX and programming Lesson 5 / Module 1 -1C2110
UNIX and programming
Petr Kulhanek
kulhanek@chemi.muni.cz
National Center for Biomolecular Research, Faculty of Science
Masaryk University, Kamenice 5, CZ-62500 Brno
PS / 2020 Distance form of teaching: Rev1
Lesson 5 / Module 1
C2110 UNIX and programming Lesson 5 / Module 1 -2Programs
vs scripts
C2110 UNIX and programming Lesson 5 / Module 1 -3Programs
vs Scripts
source code
program
input
outputtranslation (compilation)
script interpreter
input
output
Program is a set of machine instructions
processed directly by the processor. The
program is created by translatining source
code of the programming language.
Translated languages:
C/C ++
Fortran
Script is a text file containing commands
and control sequences that are executed by
the interpreter of used scripting language.
Scripting languages:
bash
gnuplot
awk
JavaScript
PHP
python
C2110 UNIX and programming Lesson 5 / Module 1 -4And
what about JAVA?
There are also different combinations of both approaches. A typical example is the Java
programming language.
Java bytecode
interpreter
JVM
input
output
source code
translation (compilation)
Java Virtual Machine
interpreter of Java bytecode
(program compiled for the
given platform - OS and HW)
Java bytecode
(platform independent - OS and HW)
C2110 UNIX and programming Lesson 5 / Module 1 -5Programs
vs Scripts, ...
➢ does not require recompilation
➢ creation self-starting code
➢ bad optimizability
➢ slower execution
➢ easy optimization
➢ fast execution
➢ must be recompiled
➢ cannot create a self-starting code
source code
program
input
outputtranslation (compilation)
script interpreter
input
output
C2110 UNIX and programming Lesson 5 / Module 1 -6Program
in C language
#include <stdio.h>
int main(int argc, char* argv[])
{
printf("This is a program in language C!\n");
return (0);
}
Compilation
$ gcc program.c -o program
Source code
Starting the program
$ ./program
compiler of C language the name of the file with the
created program
file program must have rights to be execute
C2110 UNIX and programming Lesson 5 / Module 1 -7Bashi
Script
#!/bin/bash
echo 'This is a script in Bash interpreter!'
Run the script
Bash interpreter
file script.bash does not have to have rights
to be executed
Script
$ bash script.bash
C2110 UNIX and programming Lesson 5 / Module 1 -8Exercise
1
1. Create directories with names ukol01 and ukol02.
2. To each directory, one by one save the files program.c (ukol01) and script.bash (ukol02)
from the directory ~kulhanek/Documents/C2110/Lesson05/programs.
3. Compile the source code of a program written in C. Verify that the resulting program
can be run.
4. What is the size of the file containing the resulting program created by compiling the
source code in C language. Open the created file in a text editor (gedit). What does the
file contain?
5. Verify the functionality of the script script.bash by launching it.
6. Make a copy of the files named program2.c and script2.bash.
7. Change files program2.c and script2.bash, so that the resulting program or script prints
a different text.
I recommend that you save the tasks in directories
according to the lessons and modules:
Documents/C2110/Lesson05/M1, etc.