Shell Programming and Scripting

computer
random access memory
computer networking
mouse
terminal
windows

use descriptive titles when posting for example do not post questions with subjects like help me urgent or doubt post subjects like execution problems with cron or help with backup shell script.

#!/usr/bin/perl
print "Enter a File name :";
chomp ($file = <STDIN>);
print "\n Searching file :";
if (-e $file)
{
    print "File Found\n";

    $lines = `wc -l < $file`;
    chomp $lines;

    print "Total number of lines in the file = $lines \n";

    print "Enter the pattern to search :";
    chomp ($pattern = <STDIN>);
    print "\n";
    # to search the no of words (pattern search)
    $abc=`grep "$pattern" $file`;
    print "here are the results ...\n$abc\n";
}
else{
    print "File not Found\n";
}

computer
random access memory
computer networking
mouse
terminal
windows

rom
flash

random access memory is a form of computer data storage today it takes the form of integrated circuits that allow stored data to be accessed in any order with a worst case performance of constant time strictly speaking modern types of dram are therefore not random access as data is read in bursts although the name dram ram has stuck however many types of sram rom otp and nor flash are still random access even in a strict sense ram is often associated with volatile types of memory such as dram memory modules where its stored information is lost if the power is removed many other types of non-volatile memory are ram as well, including most types of rom and a type of flash memory called nor flash the first ram modules to come into the market were created in and were sold until the late and early however other memory devices magnetic tapes disks can access the storage data in a predetermined order because mechanical designs only allow this

//Match patterns from several files.

#define _GNU_SOURCE

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<inttypes.h>

char *chomp ( char * );
void read_file ( char * , int32_t * );

int32_t main ( int32_t argc , char ** argv )
{
    char *dat_line = NULL;
    char *txt_line = NULL;
    char *file_name_txt = NULL;
    char *file_name_dat = NULL;
    char *entire_dat_file = NULL;
    char *line_from_txt_file = NULL;
    char *chomped_line = NULL;


    int32_t summation = 0;
    int32_t value = 0;
    float average = 0.0;

    int32_t dat_len = 0;
    int32_t read;
    int32_t txt_len = 0;
    int32_t number_of_characters = 0;
    int32_t number_of_words = 0;

    FILE *open_dat_file = NULL;
    FILE *open_txt_file = NULL;
    FILE *output = NULL;

    //let get the TXT files...
    system ("ls -1 *.txt > text_files.tmp" );
    
    //lets get the DAT files...
    system ( "ls -1 *.dat > dat_files.tmp" );

    //Outer look is for the DAT files and inner loop is for the TXT
    //files...

    FILE *txt_pointer = NULL;
    txt_pointer = fopen ( "text_files.tmp" , "r" );
    if ( txt_pointer == NULL )
    {
        fprintf ( stderr , "The file list for text files does not exist\n" );
    }

    FILE *dat_pointer = NULL;
    dat_pointer = fopen ( "dat_files.tmp" , "r" );
    if ( dat_pointer == NULL )
    {
        fprintf ( stderr , "The file list for the dat files does not exist\n" );
    }


    output = fopen ( "average_values.res" , "a" );
    if ( output == NULL )
    {
        fprintf ( stderr , "File append error\n" );
    }


    while ( ( read = getline ( &dat_line , &dat_len , dat_pointer ) ) != -1 )
    {
        file_name_dat = chomp ( dat_line );
        open_dat_file = fopen ( file_name_dat , "r" );

        ( void ) fseek ( open_dat_file , 0L , SEEK_END );
        number_of_characters = ftell ( open_dat_file );

        entire_dat_file = ( char * ) malloc ( number_of_characters * sizeof ( char ) );
        if ( entire_dat_file == NULL )
        {
            fprintf ( stderr , "malloc() memory allocation failure in entire_dat_file\n" );
        }

        rewind ( open_dat_file );

        read_file ( file_name_dat , &number_of_words );

        fgets ( entire_dat_file , number_of_characters , open_dat_file );

        while ( ( read = getline ( &txt_line , &txt_len , txt_pointer ) ) != -1 )
        {
            file_name_txt = chomp ( txt_line );
            open_txt_file = fopen ( file_name_txt , "r" );
            value++;

            //Now read to read the txt files one by one and search for the pattern...
        

            while ( ( read = getline ( &line_from_txt_file , &txt_len , open_txt_file ) ) != 1 && !feof ( open_txt_file ) )
            {
                chomped_line = chomp ( line_from_txt_file );
                if ( strstr ( entire_dat_file , chomped_line ) != NULL )
                {
                    summation = summation + value;
                }
            }
        }

        average = ( float ) summation / ( number_of_words + 1 );
        fprintf ( output , "%f\n" , average );
        number_of_words = 0;
        summation = 0;
        value = 0;
        number_of_characters = 0;
        rewind ( txt_pointer );

        memset ( entire_dat_file , 0 , strlen ( entire_dat_file ) );
        fclose ( open_dat_file );
    }

    fclose ( open_txt_file );
    fclose ( output );

    if ( txt_line )
    {
        free ( txt_line );
    }

    if ( dat_line )
    {
        free ( dat_line );
    }


    return ( EXIT_SUCCESS );
}


char *chomp ( char *s )
{
    char *n = malloc( strlen( s ? s : "\n" ) );
    if( s )
        strcpy( n, s );
    n[strlen(n)-1]='\0';
    return n;
}


void read_file ( char *path , int32_t *number_of_words )
{
    FILE *pointer = NULL;

    char ch;

    pointer = fopen ( path , "r" );
    if ( pointer == NULL)
    {
        perror ( "File read error " );
    }

    (*number_of_words) = 0;

    while ( !feof ( pointer ) )
    {
        ch = fgetc ( pointer );
        if ( ch == ' ' && ch != EOF )
        {
            (*number_of_words) ++;
        }
    }

    fclose ( pointer );
}