[conspir4cy]

hi
i want to learn about how may i do an application in python that read, write and even do some functions by calling bash commands in linux

imagine this:

an app that allows you to put a value, then run a command with that value as a "-" variable, so you can do something like

Code:

#!bin/bash freq=10 #max freq2=2 freq3=3 freq4=4 freq5=5 freq6=6 #rec freq7=7 #warning freq8=8 #warning freq9=9 #warning freqmax=10 #warning freqmin=1 cpu0=/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq cpu1=/sys/devices/system/cpu/cpu1/cpufreq/scaling_max_freq cpu2=/sys/devices/system/cpu/cpu2/cpufreq/scaling_max_freq cpu3=/sys/devices/system/cpu/cpu3/cpufreq/scaling_max_freq echo $freqmax > $cpu0 echo $cpu1 $cpu2 $cpu3 | xargs -n 1 cp $cpu0

but... by choosing or writing the freq value using a gui or even options in a command-line python script.

something like "processor.py -freq 1"

[obnoxious]

With read write I supposed you mean reading/writing files? There's a method in python called open.

Code:

file = open( "testfile", "w" ) # Open the file in writing mode file.write( "first line\n" ) # Write to it file.write( "second line\n" ) # Write another line file.close() # Close the file handle file = open( "testfile", "r" ) # Open the file in reading mode for i, line in enumerate( file ): # Loop through all the lines in the file     print( "Line: %s  Value: %s" % ( i, line ) )

To run a command in Python you could use the subprocess module

Code:

import subprocess subprocess.call( [ "ls", "-la"] )

or the os module

Code:

import os os.system( "ls -la" )

About being able to pass them as arguments to the python script itself you've got a lot of options. The simplest is to use the  sys module and optionally parse the arguments yourself depending on how advanced you want it. Here's an example of a script that prints the first argument that you pass to the script, basically an echo script, but we set it as a positional argument and force it to be passed.

Code:

import sys if __name__ == "__main__":     if len( sys.argv ) < 2:         print( "Usage: %s [text]" % ( sys.argv[0] ) ) # sys.argv[0] is the name of the script         sys.exit( 1 ) # exit with status code 1     print( sys.argv[1] ) # Print the first argument passed to the script

But as I mentioned above you'd need to parse it yourself if you want to have options starting with "-". In this case it'd be simpler to use the argparse module where you can choose what options you want and what values they need to be( int, string ) or if they're just boolean options. A basic google search would've gotten you all the answers - suggestion would be to do a trial and error and just test your way forward until you get the basic understanding of how things work, get familiar with the modules( os, sys ).

If you want to have a gui you'd need to use a library like tkinter, Qt, Gtk+, Kivy etc.

[conspir4cy]

With read write I supposed you mean reading/writing files? There's a method in python called open.

Code:

file = open( "testfile", "w" ) # Open the file in writing mode file.write( "first line\n" ) # Write to it file.write( "second line\n" ) # Write another line file.close() # Close the file handle file = open( "testfile", "r" ) # Open the file in reading mode for i, line in enumerate( file ): # Loop through all the lines in the file     print( "Line: %s  Value: %s" % ( i, line ) )

To run a command in Python you could use the subprocess module

Code:

import subprocess subprocess.call( [ "ls", "-la"] )

or the os module

Code:

import os os.system( "ls -la" )

About being able to pass them as arguments to the python script itself you've got a lot of options. The simplest is to use the  sys module and optionally parse the arguments yourself depending on how advanced you want it. Here's an example of a script that prints the first argument that you pass to the script, basically an echo script, but we set it as a positional argument and force it to be passed.

Code:

import sys if __name__ == "__main__":     if len( sys.argv ) < 2:         print( "Usage: %s [text]" % ( sys.argv[0] ) ) # sys.argv[0] is the name of the script         sys.exit( 1 ) # exit with status code 1     print( sys.argv[1] ) # Print the first argument passed to the script

But as I mentioned above you'd need to parse it yourself if you want to have options starting with "-". In this case it'd be simpler to use the argparse module where you can choose what options you want and what values they need to be( int, string ) or if they're just boolean options. A basic google search would've gotten you all the answers - suggestion would be to do a trial and error and just test your way forward until you get the basic understanding of how things work, get familiar with the modules( os, sys ).

If you want to have a gui you'd need to use a library like tkinter, Qt, Gtk+, Kivy etc.

thank you so much for your help!