Linux Blog

Perl Script: Convert any given string To-Lower or To-Upper case

Below is simple perl script which converts any given string to Upper or to-Lower case ...
Here, we have used the perl Escape Sequence ( \U \L \E)

\U -- Convert all following letters to Uppercase
\L -- Convert all following letters to Lowercase
\E -- Ends the effect of \L, \U or \Q

Feel free to copy and use this code ...

Source: cat case-conversion.pl
#!/usr/bin/perl

print "Enter the string: ";
$var = <STDIN>;

print "To uppercase: \U${var}\E \n";
print "To lowercase: \L${var}\E \n";

Output: perl case-conversion.pl
Enter the string: LinuxPoison
To uppercase: LINUXPOISON
To lowercase: linuxpoison

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Bash Script: Script to check internet connection

Below is simple bash script to test the Internet connection using wget utility.
Feel free to copy and use this script

Source: cat internet_connection.sh
#!/bin/bash

HOST=$1
WGET="/usr/bin/wget"

$WGET -q --tries=10 --timeout=5 $HOST
RESULT=$?

if [[ $RESULT -eq 0 ]]; then
echo "Connection made successfully to $HOST"
else
echo "Fail to make connection to $HOST"
fi

Output:
./internet_connection.sh http://yahoo.com
Connection made successfully to http://yahoo.com

./internet_connection.sh http://yahosssss.com
Fail to make connection to http://yahosssss.com

Bash Script: Commenting out the block of code using here document

Many times it required to comment out the huge block of code for debugging purpose and it is very annoying to put the "#" tag before each and every line of this code

Below shell script shows how to comment out the block of code using here document (: <<'COMMENT')

Source: cat comment_block.sh
#!/bin/bash

echo "statement before comment."
: <<'COMMENT'
echo "This is inside the comment block and will not get printed"
a=0
b=20
echo $((b/a))
echo "No error"
COMMENT

echo "This is after the comment block."
exit

Output: ./comment_block.sh
statement before comment.
This is after the comment block.

Bash Script: Transfer files through FTP from within script

Below shell script demonstrate the usage of FTP operation from within the bash script, feel free to copy and use this script:

Source: cat autoftp.sh
#!/bin/bash

if [ $# -ne 1 ]; then
echo "Please provide the file path for ftp operation."
exit
fi

USERNAME=linuxpoison
PASSWORD=password
FILENAME="$1"
FTP_SERVER=ftp.foo.com
echo "Starting the ftp operation ...."

ftp -n $FTP_SERVER <<Done-ftp
user $USERNAME $PASSWORD
binary
put "$FILENAME"
bye
Done-ftp

echo "Done with the transfer of file: $FILENAME"
exit

Output: ./autoftp.sh log.tar.gz
Starting the ftp operation ....
Done with the transfer of file: log.tar.gz