Efficiently Repeat Text


 
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# 1  
Old 04-22-2010
Efficiently Repeat Text

Hi,

Often when I use echo statements in scripts I echo a line of #'s above and below. For example:

Code:
echo #####
echo hello world
echo #####

However, I generally have a series of about 75 #'s. For example:

Code:
echo #(x 75)
echo hello world
echo #(X 75)

While this helps to delineate sections in my terminal output, my code is filled with lines of #'s. Is there a way to tell the echo command to repeat a # 75 times, so I don't have to type them individually?
# 2  
Old 04-22-2010
Hi.

There is a few good answers here: https://www.unix.com/shell-programmin...er-printf.html

Modifying post #8 from vgersh99 slightly to fit your needs:
Code:
awk 'BEGIN{$75=OFS="#";print}'

# 3  
Old 04-23-2010
What I do in many of my scripts is create a function at the beginning called separator and then whenever I need to separate things, I just call on it.

Code:
$cat example
separator () #Function that draws separator
    {
        printf "${LB}==============================================================================================================${N}\n"
    }
separator 
echo "This is an example"
separator 

$./example
==============================================================================================================
This is an example
==============================================================================================================

Edit: The {LB} and {N} are there because in the script I copied this out of, I was using ANSI colour codes to colour the separator.
# 4  
Old 04-23-2010
Quote:
Originally Posted by thegeek
When you can write function, you can do lot of optimization such as

Code:
separator()
{
for (( i=0 ; i<$1 ; i++ )) ;
do
        echo -n "#"
done
}

separator 10;

Sorry to thread jack. I'm pretty familiar with bash functions, and I use them regularly in my scripting, but I was wondering if you could just give me an idiots guide of the loop you wrote there. I understand what it's doing, but I don't really know the C style i++...etc notation.

I know I could get the same results with:

Code:
sep ()
{
    i=0;
    while [[ $i -lt $1 ]]; do
        echo -n "#";
        i=$(($i + 1));
    done
}
[~]$ sep 10
##########

But I'd like to understand your way (and know if there is an advantage of yours over mine).
# 5  
Old 04-23-2010
Combining the other methods into a slightly shorter idea:

Code:
separator()
{
awk -v num=$1 'BEGIN{$num=OFS="#";print}'
}

separator 10;

# 6  
Old 04-23-2010
Quote:
Originally Posted by DeCoTwc
Sorry to thread jack. I'm pretty familiar with bash functions, and I use them regularly in my scripting, but I was wondering if you could just give me an idiots guide of the loop you wrote there. I understand what it's doing, but I don't really know the C style i++...etc notation.
Code:
#!/bin/bash
# The first expression is evaluated once, before the loop is entered.
# Usually used for assignments.  You could put more than one, separated
# by commas, but that's almost never done.

# The second is a condition.  Whenever it's true, it continues looping.
# If you put 0, the inner loop would never be executed at all.  If you put 1, it'd loop forever.

# The third expression is evaluated after every loop.  Usually used to
# increase a value but you could put any expression there.

# the do/done section is just like a while.
for ((  N=0 ; N<10 ; N++ ))
do
        echo "ASDF"
done

These structures work in bash and newer versions of ksh, but don't work in minimal or old implementations of sh.

---------- Post updated at 02:16 PM ---------- Previous update was at 02:14 PM ----------

Quote:
Originally Posted by treesloth
Combining the other methods into a slightly shorter idea:

Code:
separator()
{
awk -v num=$1 'BEGIN{$num=OFS="#";print}'
}

separator 10;

Forking off an external process to do it for you is not an efficient way to print ten hatch marks.

Personally, I'd just do:

Code:
SEPARATOR="##############"

then just "echo $SEPERATOR" whenever I need to.
# 7  
Old 04-23-2010
Quote:
Originally Posted by Corona688
Forking off an external process to do it for you is not an efficient way to print ten hatch marks.
No, it isn't, but recall that that's not the point of doing it that way.
 
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