CURL can be used very effectively using PHP. Here is an example.

cat curl.php

<?php
$ch = curl_init("www.google.com");
$fp = fopen("example.txt", "w");

curl_setopt($ch, CURLOPT_FILE, $fp);
curl_setopt($ch, CURLOPT_HEADER, 0);

curl_exec($ch);
curl_close($ch);
fclose($fp);
?>

cat myawk.sh

!/bin/sh

list the type of files with count

find ${*-.} -type f -print | xargs file |
awk '{
$1=NULL;
t[$0]++;
}
END {
for (i in t) printf("%d\t%s\n", t[i], i);
}' | sort -nr

HashKnownHosts no
Add the above line in your ssh_config file that can be found here....
/etc/ssh/ssh_config

If you need to know the 3 days old date, it easy in shell.

$ v_prev_date=date --date='3 days ago' +%Y%m%d

$ echo $v_prev_date
20090808

perl -pe '$ = "$. $"'

“-p” causes Perl to assume a loop around the program (specified by “-e”) that reads each line of input into the ” $ ” variable, executes the program and then prints the ” $ ” variable. In this one-liner I simply modify ” $_ ” and prepend the ” $. ” variable to it. The special variable ” $. ” contains the current line number of input.
The result is that each line gets its line number prepended.

$ cat salaries
Yvette van der Hoff 100000
Sarack Abama 400000
Bernie Madoff 0
John Q. Public 20000

$ awk '{print $NF, $0}' salaries | sort -nr -k1,1 | cut -d" " -f2-
Sarack Abama 400000
Yvette van der Hoff 100000
John Q. Public 20000
Bernie Madoff 0

$ awk -F '\t' -v 'OFS=\t' '{print $4, $3, $5, $2, $1}' data.txt
POP. COUNTY GOVT. CITY STATE
123 Gila Mayor Ely AZ
345 Lolo Sheriff Alma CA
22 El Paso Bubba Leroy TX

at -v 03:00 -f /root/shantanu/testat.sh > /root/shantanu/testat_result.txt 2>&1

atq

7 2009-03-14 03:00 a root

30 0 * updatedb > /dev/null 2>&1

Clock synchronization

30 10 CTIPDGT=`/sbin/ifconfig | grep -m 1 "inet addr" | grep -o "17.2.[0,8,26,32,40,56,16,40,56]." | cut -d "." -f3`; /usr/sbin/ntpdate -u 172.29.${CTIPDGT}.123; /sbin/hwclock --systohc > /dev/null 2>&1

The declare command can be helpful in identifying variables, environmental or otherwise. This can be especially useful with arrays.

bash$ declare | grep HOME
/home/bozo

bash$ zzy=68
bash$ declare | grep zzy
zzy=68

bash$ Colors=([0]="purple" [1]="reddish-orange" [2]="light green")
bash$ echo ${Colors[@]}
purple reddish-orange light green
bash$ declare | grep Colors
Colors=([0]="purple" [1]="reddish-orange" [2]="light green")