ProvaPratica 2013.05.29 - Revision history

FedericoB: Aggiunto link e testo del es 1

2017-05-10T16:16:03Z

Aggiunto link e testo del es 1

FedericoB: Aggiunte soluzioni da altre pagine, uniformato

2017-05-10T07:19:11Z

Aggiunte soluzioni da altre pagine, uniformato

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Edu san at 01:22, 14 May 2014

2014-05-14T01:22:04Z

Pirata at 18:16, 3 December 2013

2013-12-03T18:16:57Z

Pirata at 18:16, 3 December 2013

2013-12-03T18:16:06Z

Edu san at 01:37, 28 November 2013

2013-11-28T01:37:47Z

Edu san at 01:37, 28 November 2013

2013-11-28T01:37:22Z

Edu san at 01:29, 28 November 2013

2013-11-28T01:29:49Z

Edu san at 01:14, 28 November 2013

2013-11-28T01:14:06Z

Amonaldini at 18:51, 27 November 2013

2013-11-27T18:51:01Z

← Older revision		Revision as of 16:16, 10 May 2017
Line 1:		Line 1:
		+	[http://www.cs.unibo.it/~renzo/so/pratiche/2013.05.29.pdf Link al compito]
	==Esercizio 1==		==Esercizio 1==
		+
		+	<source lang="text">
		+	Scrivere un programma testeventfd che faccia uso della system call eventfd.
		+	In particolare il programma deve eseguire una fork, quando l'utente digita un numero letto dal processo padre, il processo
		+	figlio deve stampare un numero uguale di x.
		+	$ testeventfd
		+	3
		+	x
		+	x
		+	x
		+	2
		+	x
		+	x
		+	</source>

	===Soluzione di GiuliaN.===		===Soluzione di GiuliaN.===

← Older revision		Revision as of 01:22, 14 May 2014
Line 302:		Line 302:
	--edit: dir_list = os.listdir(target_dir) non funzionava bene coi path relativi.		--edit: dir_list = os.listdir(target_dir) non funzionava bene coi path relativi.
	Ora os.listdir('.') dovrebbe andare bene.		Ora os.listdir('.') dovrebbe andare bene.
		+
		+	--------
		+	[es.2 - C]
		+	<syntaxhighlight lang="C">
		+	#include <stdio.h>
		+	#include <stdlib.h>
		+	#include <unistd.h>
		+	#include <sys/types.h>
		+	#include <sys/eventfd.h>
		+
		+	#define SIZE 64
		+
		+	int main(int argc, char **argv){
		+	int efd_parent, efd_child;
		+	pid_t pid;
		+
		+	efd_parent = eventfd(0, 0);
		+	efd_child = eventfd(0, 0);
		+
		+	pid = fork();
		+	if(pid < 0){
		+	perror("Fork error. ");
		+	exit(EXIT_FAILURE);
		+	}
		+	/* parent */
		+	if(pid){
		+	int okToWrite = 1;
		+	ssize_t n;
		+	char buf[SIZE];
		+
		+	for(;;){
		+	if(okToWrite){
		+	scanf("%s", buf);
		+
		+	n = write(efd_parent, buf, SIZE);
		+	if(n < 0){
		+	perror("Parent: write error.");
		+	exit(EXIT_FAILURE);
		+	}
		+	okToWrite = 1-okToWrite;
		+	}
		+	else{
		+	n = read(efd_child, buf, SIZE);
		+	if( n < sizeof(uint64_t) ){
		+	printf("Parent: something bad happened");
		+	exit(EXIT_FAILURE);
		+	}
		+
		+	printf("padre: %s\n", buf);
		+	okToWrite = 1-okToWrite;
		+	}
		+	}
		+	close(efd_parent);
		+	}
		+	/* child */
		+	else{
		+	int okToWrite = 0;
		+	char buf[SIZE];
		+	int n;
		+
		+	for(;;){
		+	if(okToWrite){
		+	scanf("%s", buf);
		+
		+	n = write(efd_child, buf, SIZE);
		+	if(n < 0){
		+	perror("child: write error.");
		+	exit(EXIT_FAILURE);
		+	}
		+	okToWrite = 1-okToWrite;
		+	}
		+	else{
		+	n = read(efd_parent, buf, SIZE);
		+	if( n < sizeof(uint64_t) ){
		+	printf("Child: something bad happened");
		+	exit(EXIT_FAILURE);
		+	}
		+	printf("figlio: %s\n", buf);
		+	okToWrite = 1-okToWrite;
		+	}
		+	}
		+	close(efd_child);
		+	}
		+
		+	return EXIT_SUCCESS;
		+	}
		+	</syntaxhighlight>
		+	- Eduardo

@@ Line 204: / Line 204: @@
 		uint64_t b;
 		read( efd , &b , sizeof( b ) );
 		printf( "x\n" );
+		}

← Older revision		Revision as of 18:16, 3 December 2013
Line 174:		Line 174:
	</syntaxhighlight>		</syntaxhighlight>
	GiuliaN. con grande aiuto da parte dei colleghi		GiuliaN. con grande aiuto da parte dei colleghi
		+
		+
		+
		+
		+	Esercizio 1:(visto a lezione , soluzione del Prof. Davoli Pirata_20131203)
		+	<syntaxhighlight lang="C">
		+	#include <sys/eventfd.h>
		+	#include <stdio.h>
		+	#include <stdint.h>
		+	#include <stdlib.h>
		+	#include <unistd.h>
		+
		+	#define BUFFSIZE 10
		+
		+	int main(int argc, char *argv[]){
		+	int efd , n , i;
		+	uint64_t a , b;
		+	if ( ( efd = eventfd( 0 , EFD_SEMAPHORE ) ) < 0 )
		+	exit( 1 );
		+	if ( fork() > 0 ){
		+	while ( 1 ) {
		+	uint64_t a;
		+	scanf( "%lld" , &a );
		+	write( efd , &a , sizeof( a ) );
		+	}
		+	}
		+	else {
		+	while ( 1 ) {
		+	uint64_t b;
		+	read( efd , &b , sizeof( b ) );
		+	//for ( i = 0 ; i < b ; i++ )
		+	printf( "x\n" );
		+	}
		+	}
		+	}
		+	</syntaxhighlight>
		+

@@ Line 264: / Line 264: @@
 </syntaxhighlight>
 -Eduardo
-edit: dir_list = os.listdir(target_dir) non funzionava bene coi path relativi.
+--edit: dir_list = os.listdir(target_dir) non funzionava bene coi path relativi.
 Ora os.listdir('.') dovrebbe andare bene.

@@ Line 249: / Line 249: @@
 	target_dir = '.'
 os.chdir(target_dir)
-dir_list = os.listdir(target_dir)
+dir_list = os.listdir('.')
 # For each file call get_suffix and then build_dict
@@ Line 264: / Line 264: @@
 </syntaxhighlight>
 -Eduardo

@@ Line 194: / Line 194: @@
 </syntaxhighlight>
 Per (Pirata & Fede) -Bash-: ci siamo quasi...però forse rifate gli stessi calcoli un po' di volte in più del necessario ;-) (am_20131127).
 [Esercizio 3 in Python (ancora)]

← Older revision		Revision as of 01:14, 28 November 2013
Line 194:		Line 194:
	</syntaxhighlight>		</syntaxhighlight>
	Per (Pirata & Fede) -Bash-: ci siamo quasi...però forse rifate gli stessi calcoli un po' di volte in più del necessario ;-) (am_20131127).		Per (Pirata & Fede) -Bash-: ci siamo quasi...però forse rifate gli stessi calcoli un po' di volte in più del necessario ;-) (am_20131127).
		+
		+	[Esercizio 3 in Python (ancora)]
		+
		+	<syntaxhighlight lang="Python">
		+	#!/usr/bin/env python3
		+	#
		+	# Prova Pratica di Lab SO 2013.05.29
		+	# Es. 3
		+	# Eduardo Santarelli
		+	#####################################
		+
		+	import os, sys
		+
		+	# return the suffix of file named fname, if present.
		+	# return boolean value False otherwise
		+	def get_suffix(fname):
		+	if '.' in fname:
		+	separator = fname.find('.')
		+	return fname[separator : ]
		+	else:
		+	return False
		+
		+	# Place a file in a dictionary. Each key corresponds
		+	# to a specific suffix, its value is a list of all the
		+	# file with that suffix
		+	def build_dict(item, suffix):
		+	if suffix in all_files:
		+	all_files[suffix].append(item)
		+	else:
		+	all_files[suffix] = []
		+	all_files[suffix].append(item)
		+
		+	# For each suffix key in the dictionary,
		+	# calculates the total size of the files
		+	# in the corresponding list
		+	def size_of_entry(file_list):
		+	size = 0
		+	for item in file_list:
		+	size += os.path.getsize(item)
		+	return size
		+
		+	# This dictionary will contain a key for each suffix,
		+	# associated with a list of all the files ending with
		+	# that suffix
		+	all_files = dict()
		+
		+	# Go to target directory and build a list containing all filenames
		+	try:
		+	target_dir = sys.argv[1]
		+	except:
		+	target_dir = '.'
		+	os.chdir(target_dir)
		+	dir_list = os.listdir(target_dir)
		+
		+	# For each file call get_suffix and then build_dict
		+	# (unless get_suffix returns False)
		+	for item in dir_list:
		+	suffix = get_suffix(item)
		+	if not suffix:
		+	pass
		+	else:
		+	build_dict(item, suffix)
		+
		+	for key in all_files :
		+	print("{0}: {1} Bytes".format(key, size_of_entry(all_files[key])))
		+	</syntaxhighlight>
		+	-Eduardo

← Older revision		Revision as of 18:51, 27 November 2013
Line 193:		Line 193:
	done		done
	</syntaxhighlight>		</syntaxhighlight>
		+	Per (Pirata & Fede) -Bash-: ci siamo quasi...però forse rifate gli stessi calcoli un po' di volte in più del necessario ;-) (am_20131127).