DZone Snippets: Tvrtko's Code Snippets

Listing the files and subdirectories in C - Linux

Tvrtko (Tvrtko) — Tue, 08 Jul 2008 01:13:50 GMT

// program lists the files and subdirectories within a given directory in full path



#include 

#include 

#include 

#include 



char *path_cat (const char *str1, char *str2);



int main () {

	struct dirent *dp;



        // enter existing path to directory below

	const char *dir_path="/path/to/directory/to/list";

	DIR *dir = opendir(dir_path);

	while ((dp=readdir(dir)) != NULL) {

		char *tmp;

		tmp = path_cat(dir_path, dp->d_name);

		printf("%s\n", tmp);

		free(tmp);

		tmp=NULL;

	}

	closedir(dir);

	return 0;

}



char *path_cat (const char *str1, char *str2) {

	size_t str1_len = strlen(str1);

	size_t str2_len = strlen(str2);

	char *result;

	result = malloc((str1_len+str2_len+1)*sizeof *result);

	strcpy (result,str1);

	int i,j;

	for(i=str1_len, j=0; ((i<(str1_len+str2_len)) && (j		result[i]=str2[j];

	}

	result[str1_len+str2_len]='\0';

	return result;

}

C functions for getting disk space information in Linux OS

Tvrtko (Tvrtko) — Fri, 06 Jun 2008 16:41:22 GMT

These are 2 C functions for getting disk capacity and disk free space in megabytes into char array



#include 

#include 



gchar *

g_get_capacity ( gchar * dev_path)

{

	unsigned long long result = 0;

	int n;

	gchar s_cap[50];

	gchar * ss_cap = "N/A";

	struct statvfs sfs;

	if ( statvfs ( dev_path, &sfs) != -1 )

	{

		result = (unsigned long long)sfs.f_bsize * sfs.f_blocks;

	}

	if (result > 0)

	{

		double f_cap = (double)result/(1024*1024);

		n = sprintf(s_cap, "%.2f Mb", f_cap);

		ss_cap = g_strdup(s_cap);

	}

	return ss_cap;

}



gchar * 

g_get_free_space ( gchar * dev_path)

{

	unsigned long long result = 0;

	int n;

	gchar s_cap[50];

	gchar * ss_cap = "N/A";

	struct statvfs sfs;

	if ( statvfs ( dev_path, &sfs) != -1 )

	{

		result = (unsigned long long)sfs.f_bsize * sfs.f_bfree;

	}

	if (result > 0)

	{

		double f_cap = (double)result/(1024*1024);

		n = sprintf(s_cap, "%.2f Mb", f_cap);

		ss_cap = g_strdup(s_cap);

	}

	return ss_cap;

}

C++ code to HTML

Tvrtko (Tvrtko) — Wed, 07 May 2008 15:59:25 GMT

generate html colored file from a source file



#include 

#include 

#include 

#include 

#include 

using namespace std;



#include 



const char * expressions =

	// comments

	"(//[^\\n]*|/\\*.*?\\*/)|"

	// precompilers

	"(^[[:blank:]]*#[^\\n]*)|"

	// string literals

	"(\"(?:[^\\\\\"]|\\\\.)*\"|'(?:[^\\\\']|\\\\.)*')|"

	// floating point literal

	"(\\<[[:digit:]]+\\.[[:digit:]]+)|"

	//  integer literal

	"(\\<[[:digit:]]+\\>)|"

	// boolean literal

	"((?:\\)|(?:\\))|"

	// keywords

	"\\<(__asm|__cdecl|__declspec|__export|__far16|__fastcall|__fortran|__import"

	"|__pascal|__rtti|__stdcall|_asm|_cdecl|__except|_export|_far16|_fastcall"

	"|__finally|_fortran|_import|_pascal|_stdcall|__thread|__try|asm|auto|bool"

	"|break|case|catch|cdecl|char|class|const|const_cast|continue|default|delete"

	"|do|double|dynamic_cast|else|enum|explicit|extern|false|float|for|friend|goto"

	"|if|inline|int|long|mutable|namespace|new|operator|pascal|private|protected"

	"|public|register|reinterpret_cast|return|short|signed|sizeof|static|static_cast"

	"|struct|switch|template|this|throw|true|try|typedef|typeid|typename|union|unsigned"

	"|using|virtual|void|volatile|wchar_t|while)\\>";



const char * format = 

	"(?1$&)"

	"(?2$&)"

	"(?3$&)"

	"(?4$&)"

	"(?5$&)"

	"(?6$&)"

	"(?7$&)";



string help = 

	"Usage:"

	"\n\nccode2html  "

	"\n\nIf output filename is omitted its name it will be .html";

string code_tag_start = "";

string code_tag_end = "";



void ccode2html (string input, string output);

string test();



extern const char* pre_expression = "(<)|(>)|(&)|\\r";

extern const char* pre_format = "(?1\\<)(?2\\>)(?3&)";



int main (int argc, char *argv[])

{

	string input_file;

	string output_file;

	if (argc > 3 || argc==1) {

		cout << help;

		exit(0);

	}

	else if (argc==2) {

		input_file=argv[1];

		output_file=input_file+".html";

		ccode2html (input_file, output_file);

	} else {

		input_file=argv[1];

		output_file=argv[2];

		ccode2html (input_file, output_file);

	}

	return 0;

}



// ccode2html method



void ccode2html (string input, string output)

{

	try {

		boost::regex e1, e2;

		e2.assign(pre_expression);

		e1.assign(expressions);

		fstream in (input.c_str(), fstream::in);

		fstream out (output.c_str(), fstream::out);

		out << "";

		string ins;

		char c;

		while (in.get (c)) {

			ins.append (1, c);

		}

		ostringstream t(std::ios::out | std::ios::binary);

		ostream_iterator io(t);

		boost::regex_replace(io, ins.begin(), ins.end(), e2, pre_format, 

				boost::match_default | boost::format_all);

		string s(t.str());

		std::ostream_iterator o(out);

		boost::regex_replace(o, s.begin(), s.end(), e1, format,

				boost::match_default | boost::format_all);

		out << "";

		cout << s;

		cout << input << endl;

		cout << output << endl;

		test();

	} catch (char * exc) {

		cout << "errors:" << endl;

		cout << exc << endl;

	}

}

Put mounted drives list into Glist

Tvrtko (Tvrtko) — Sat, 12 Apr 2008 13:22:02 GMT

Function that gets list of mounted drives from '/etc/fstab' and '/etc/mtab' files and puts data in the GList object (from GLib library) that can be further used in GTK.



#include 

#include 

#include 



GList * g_get_drives_list(GList * g) {

	FILE *fstab = NULL;

	struct mntent *part = NULL;

	gchar *mntp = NULL;

	

	if ((fstab = setmntent( "/etc/fstab", "r" )) != NULL) {

		while ((part = getmntent(fstab))  != NULL) {

			if((strcmp(part->mnt_type, "proc")) != 0 && (strcmp(part->mnt_type, "devpts")) != 0 

																					&& (strcmp(part->mnt_type, "swap")) != 0) {

				mntp = g_strdup(part->mnt_dir);

				g=g_list_append(g, mntp);

			}

		}

		endmntent(fstab);

	}

	

	if ((fstab = setmntent( "/etc/mtab", "r")) != NULL) {

		while ((part = getmntent(fstab)) != NULL) {

			if (part->mnt_type != NULL) {

				if((strcmp(part->mnt_type, "proc")) != 0 && (strcmp(part->mnt_type, "devpts")) != 0

						&& (strcmp(part->mnt_type, "swap")) != 0 && (strcmp(part->mnt_type, "sysfs")) != 0

						&& (strcmp(part->mnt_type, "tmpfs")) != 0 && (strcmp(part->mnt_type, "fuseblk")) != 0

						&& (strcmp(part->mnt_type, "securityfs")) != 0) {

					if((g_list_find_custom(g, part->mnt_dir, (GCompareFunc)strcmp)) == 0) {

						mntp=g_strdup(part->mnt_dir);

						g=g_list_append(g, mntp);

					}

				}

			}

		}

		endmntent(fstab);

	}

	return g;

}

Code 2 HTML

Tvrtko (Tvrtko) — Mon, 07 Apr 2008 07:59:48 GMT

This is a simple python program that reads a file (code), and replaces line breaks and spaces with appropriate tag and entity.



import sys



line_break='
'

nb_space=' '



def toHtml(f,out):

    try:

        fo=open(out,'w')

    except IOError:

        print 'output file error!'

    else:

        for line in f:

            line=line.replace('\t',nb_space*8)

            line=line.replace(' ',nb_space)

            line=line.replace('\n',line_break)

            fo.write(line)

        fo.close()

        



if len(sys.argv) == 1:

    print("at least one argument / input filename / required")

    sys.exit()

if len(sys.argv) > 3:

    print"too many arguments"

    sys.exit()       

try:

    f=open(sys.argv[1],'r')

except IOError:

    print 'cannot open file ', sys.argv[1]

else:

    if len(sys.argv) == 2:

        out=f.name + '.html'

    else:

        out=sys.argv[2]

    toHtml(f, out)

    f.close()

decompressing various archive types

Tvrtko (Tvrtko) — Sun, 06 Apr 2008 22:31:57 GMT

// decompressing various archive types with this python script
// usage unpack



#!/usr/bin/env python

#

# simple python script for extracting mostly used types of archives

# this script extracts .tar, .tar.gz, .tar.bz2, .gz and .zip archives 

#



import sys	# required for fetching command line arguments 

import os	# required for calling commands for archive extracting



def unpack(s):									# this is definition of depack

	if (s.find('.tar.gz') != -1):				#	function. It takes string

		os.system("tar -xvvzf " + filename)		#   filename as argument.

	elif (s.find('.tar.bz2') != -1):			#	functon than calls 

		os.system("tar -xvvjf " + filename)		#   appropriate command according

	elif (s.find('.tar') != -1):				# 	to file extension

		os.system("tar -xvvf " + filename)

	elif (s.find('.gz') != -1):

		os.system("gunzip" + filename)			

	elif (s.find('.zip') != -1):		

		os.system("unzip " + filename)

	else: print "Wrong archive or filename"		# other types not supported



try:											# this is main program

	filename = sys.argv[1]						# first argument right after

	unpack(filename)							#	'unpack' command goes in the

except IndexError:								#	filename string

	print "Filename is invalid!"				#	than the depack function is called



# try-except block is used for handling IndexError exception if no argument is passed