Visit Our UNIX and Linux User Community


Escaping Special characters


 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting Escaping Special characters
# 1  
Old 10-26-2009
Escaping Special characters

I want to append the following line to /var/spool/cron/root:
Code:
*/7 * * * * /root/'Linux CPU (EDF).sh' > /dev/null 2>&1

How to accomplish this using echo?

---------- Post updated at 04:09 PM ---------- Previous update was at 04:07 PM ----------

"Linux CPU (EDF)" is actually stored in a variable named Service_Name

---------- Post updated at 04:13 PM ---------- Previous update was at 04:09 PM ----------

I am using the command:

Code:
echo "*/7 * * * * /root/\'"$Service_Name".sh\' >/dev/null 2>&1" >> /var/spool/cron/root

# 2  
Old 10-26-2009
Use

Code:
echo "*/7 * * * * /root/'$Service_Name'.sh > /dev/null 2>&1" >> root

It's generally not a good idea to manually modify the crontab file in this way. You should use crontab.

Last edited by Scott; 10-26-2009 at 06:49 PM..
# 3  
Old 10-26-2009
But the Service_Name variable contains "Linux CPU (EDF)", which has got spaces in between. I need to escape those spaces..
# 4  
Old 10-26-2009
Code:
echo "*/7 * * * * /root/'$Service_Name'.sh > /dev/null 2>&1" >> root

You don't need to escape anything.

Code:
A=" '1 2 3' "

echo $A
'1 2 3'

# 5  
Old 10-26-2009
I thought single quote reduces the significance of special characters including $.
# 6  
Old 10-26-2009
Not when they're enclosed in double quotes. The opposite isn't true.

Code:
A=" '1 2 3' "

echo "$A"
'1 2 3'

A=' "1 2 3" '
echo $A
"1 2 3"

echo '$A'
$A

# 7  
Old 10-26-2009
Code:
ksspl-RandD:~$ echo $x

ksspl-RandD:~$ echo '$x'
$x



---------- Post updated at 04:59 PM ---------- Previous update was at 04:55 PM ----------

Thanks,

If we include something inside of double-quotes, everything loses its special meaning except for the variable operator ($), the back-slash (\), the back-tick (`), and the double-quote itself.

Previous Thread | Next Thread
Test Your Knowledge in Computers #553
Difficulty: Medium
The standard input (stdin for short), standard output (stdout) and standard error (stderr) are three standard communication streams that are defined by most computer systems.
True or False?

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

sed replacing specific characters and control characters by escaping

sed -e "s// /g" old.txt > new.txt While I do know some control characters need to be escaped, can normal characters also be escaped and still work the same way? Basically I do not know all control characters that have a special meaning, for example, ?, ., % have a meaning and have to be escaped... (11 Replies)
Discussion started by: ijustneeda
11 Replies

2. Shell Programming and Scripting

Replace special characters with Escape characters?

i need to replace the any special characters with escape characters like below. test!=123-> test\!\=123 !@#$%^&*()-= to be replaced by \!\@\#\$\%\^\&\*\(\)\-\= (8 Replies)
Discussion started by: laknar
8 Replies

3. Shell Programming and Scripting

special characters

Hey guys, I'm trying to replace "]Facebook" from the text but sed 's/]Facebook/Johan/g' is not working could you please help me with that? (6 Replies)
Discussion started by: Johanni
6 Replies

4. Shell Programming and Scripting

Escaping special characters

I'm attempting a little hack to get grep to highlight (change foreground color to red) a found string. Assuming a target file "test" consisting of the word "albert": My executable "algrep" consists of this: grep $1 $2 | sed "s/$1/\\\033 And when run: algrep al test Produces this:... (2 Replies)
Discussion started by: tiggyboo
2 Replies

5. Shell Programming and Scripting

Help with escaping xml characters in a file

Hi, I have a file xy.csv with the following data separated by pipe (|): BC-NACO|12>ISA43<TEST| A & A INC|FAMOUS'S AL| i need to escape the xml characters as below BC-NACO|12&gt;ISA43&lt;TEST| A &amp; A INC|FAMOUS&apos;S AL| Please advise (5 Replies)
Discussion started by: prasannarajesh
5 Replies

6. UNIX for Dummies Questions & Answers

Escaping non-readable characters using grep, sed or awk

I'm trying to parse out DNS logs from dozens of different domain controllers over a large period of time. The logs are rolled up into individual text files by size, which may contain only a portion of a day's activity or several day's worth (depending on amount of activity). I'm splitting them by... (4 Replies)
Discussion started by: seanwpaul
4 Replies

7. Shell Programming and Scripting

Special characters

When I open a file in vi, I see the following characters: \302\240 Can someone explain what these characters mean. Is it ASCII format? I need to trim those characters from a file. I am doing the following: tr -d '\302\240' ---------- Post updated at 08:35 PM ---------- Previous... (1 Reply)
Discussion started by: sid1982
1 Replies

8. Shell Programming and Scripting

Escaping Special Characters-Help

Hi All, I am having a trouble in passing special characters to a script. As I am new to bash script I dont know how to go and solve this. mypwd=(a+sdfg!h# if i pass $mypwd to a bash script, it is not accepting "(,!,+ etc". It would be a great help if some one can help to escape these... (3 Replies)
Discussion started by: Tuxidow
3 Replies

9. UNIX for Advanced & Expert Users

Escaping special character stored in variables : perl

Hi just for regular use i m working on small module written in perl for getting date in specified format like i have to specify date format and then seperator to seperate date i am 95% done. now i m sure explanation i gave is not good enough so i am putting output here : C:\Documents and... (2 Replies)
Discussion started by: zedex
2 Replies

10. Shell Programming and Scripting

escaping special characters in file name...

dear, I would like to rename files in a dir to another format, so I write a bash shell script to handle it. But my problem now is how to handle files having special characters like spaces, (, ): "a b c (d).doc" It seems that I need to escape those characters before applying the "mv" command.... (1 Reply)
Discussion started by: lau0001
1 Replies

Featured Tech Videos