We can not scroll up or down while working in screen mode. Press Ctrl-a, Esc to enter copy mode, then use standard navigation keys. Adding the following to ~/.screenrc will solve this issue.
termcapinfo xterm|xterms|xs|rxvt ti@:te@

or add this to /etc/screenrc
defscrollback 1024

hardstatus on
hardstatus alwayslastline
hardstatus string "%{.bW}%-w%{.rW}%n %t%{-}%+w %=%{..G} %H %{..Y} %m/%d %C%a "

As a quick tip, name your screen windows using Ctrl-a A

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

# cat curl.php
<?php
$ch = curl_init("http://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

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")