Korn: How to loop through a string character by character - Shell Programming and Scripting

shew01 · #1 (**permalink**) 05-28-2008

If I have a string defined as:

Code:

MyString=abcde

echo $MyString

How can I loop through it character by character? I haven't been able to find a way to index the string so that I loop through it.

shew01

aigles · #2 (**permalink**) 05-28-2008

A possible solution :

Code:

MyString=abcde
echo $MyString | awk -v ORS="" '{ gsub(/./,"&\n") ; print }' | \
while read char
do
   echo "<$char>"
done

Output:

Code:

<a>
<b>
<c>
<d>
<e>

Jean-Pierre.

aigles · #3 (**permalink**) 05-28-2008

Another way :

Code:

MyString=abcde
i=0
while (( i++ < ${#MyString} ))
do
   char=$(expr substr "$MyString" $i 1)
   echo "<$char>"
done

Jean-Pierre.

shew01 · #4 (**permalink**) 05-29-2008

Quote:

Originally Posted by aigles

A possible solution :

Code:

MyString=abcde
echo $MyString | awk -v ORS="" '{ gsub(/./,"&\n") ; print }' | \
while read char
do
   echo "<$char>"
done

Output:

Code:

<a>
<b>
<c>
<d>
<e>

Jean-Pierre.

I am running the Korn shell on Solaris 8, and I am getting errors:

Code:

awk: syntax error near line 1
awk: bailing out near line 1

Any ideas?

shew01

shew01 · #5 (**permalink**) 05-29-2008

Quote:

Originally Posted by aigles

Another way :

Code:

MyString=abcde
i=0
while (( i++ < ${#MyString} ))
do
   char=$(expr substr "$MyString" $i 1)
   echo "<$char>"
done

Jean-Pierre.

My script name is jps.ksh. Any ideas?

Code:

jps.ksh[3]:  i++ < 5 : syntax error

aigles · #6 (**permalink**) 05-29-2008

Quote:

Originally Posted by shew01

I am running the Korn shell on Solaris 8, and I am getting errors:

Code:

awk: syntax error near line 1
awk: bailing out near line 1

Any ideas?

shew01

Do you Have tried nawk instead of awk ?

Jean-Pierre.

aigles · #7 (**permalink**) 05-29-2008

Quote:

Originally Posted by shew01

My script name is jps.ksh. Any ideas?

Code:

jps.ksh[3]:  i++ < 5 : syntax error

Sorry, this syntax works with bash but not with ksh.
Try this new version of the script :

Code:

MyString=abcde
i=1
while (( i <= ${#MyString} ))
do
   char=$(expr substr "$MyString" $i 1)
   echo "<$char>"
   (( i += 1 ))
done

Jean-Pierre.

More UNIX and Linux Forum Topics You Might Find Helpful
Thread	Thread Starter	Forum	Replies	Last Post
read a variable character by character, substitute characters with something else	vipervenom25	UNIX for Dummies Questions & Answers	2	06-06-2008 12:18 PM
cut from a particular character to the end of the string	grajesh_955	Shell Programming and Scripting	2	05-25-2008 03:03 AM
Help needed in character replacement in Korn Shell	stevefox	Shell Programming and Scripting	8	03-29-2007 08:59 PM
How do I get the nth character from a string?	toughman	UNIX for Dummies Questions & Answers	4	06-22-2006 09:54 AM
Delete first 2 character from string	nitinshinde	UNIX for Dummies Questions & Answers	4	10-02-2001 05:06 PM

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode