Shell Programming and Scripting

Dear Friend,

You can execute the following in the command line

Code:

 step 1: 
 var="100,200,300"
 
 step 2: 
var1=`echo $var | sed -e 's/,/ /g'`
echo $var1

The output is
100 200 300

Older ksh88 version is not Posix compatible, because posix has done later. Most of commercial *nix still include only ksh88 version.
But you can download also ksh93 version, which is posix-compatible. Why ? I think that Posix-team has used lot of ksh93 to make posix standard.
Download binary.

Simple test, ksh88 or ksh93. Many *sh based on ksh88 ...
Ex. substr not work in older shells.

Code:

abc="1234"
substr=${abc:1:2}
echo  "<$substr>"

Posix
Utils

Hi, kshji

I don't understand how you come to the conclusion that ksh93 is somehow more posix-y than ksh88. If you take a look at the features it introduced (associative arrays, floating point arithmetic, new forms of parameter expansion, etc), 15 years later they're not part of the posix sh standard. If anything, ksh93 deviates further from the standard.

The example you chose, substring parameter expansion, exemplifies this. It is a feature that's supported by most modern variants of the bourne shell, but it is not part of posix. Any shell that does not implement it is not any less posix-compliant because of it. The same goes for the pattern/replacement parameter expansion that started this discussion. (Though they are both handy features, no doubt.)

I don't know about you, but i love shell chat

Regards,
alister

You are right.
Shell Command Language
I didn't check... I have learned this substr feature, not from ksh, it was some "posix-sh". Now I know, it wasn't . Or it was - include posix.

Dash is maybe the most of posix-compatible and only posix. I know that ksh and many other "Bourne shell child" include lot of extension features. Much more than posix shell. For me posix shell compatible means that sh include posix. I try to use only posix stuff (almost .

Anyway, parameter extension is powerful, but not so easy to read. Need always little comments for others, who are not so sh gurus. sed, tr, cut, awk, expr, .. lines are more readable, but need huge cpu if compare using of parameter extension. Not built-in.

So, my test was simple test to compare, have you ksh88 or ksh93. Nothing else.

Sorry, english it's not my main language.