Re: upper/lower case

I think Rakesh's piece of code shows the art of shell scripts. Shell
scripting is cryptic and obscure on the first sight even for someone who
knows scripting (geniuses excluded). This script could find its way to
the  Advanced Bash-Scripting Guide to show the power of shell. Its a
true gem!


On 13/12/15 00:26, Daniel Goldman [email protected] [sed-users] wrote:
> You probably did make it as modular as bash/sed would allow. I applaud 
> it. However, if you're saying you don't think it's obscure, I would 
> definitely not agree with that.
>
> I have to tread a little lightly, because "obscurity" can descend into a 
> "religious war" unless one is careful. I should just say that I was 
> hard-pressed to tell what is going to happen by scanning the code, and I 
> am no newbie. Based on my experience, I think the great majority of 
> programmers would be hard pressed, but that is just my opinion. In 
> contrast, the cut-paste solution is pedestrian, but each step seems 
> clear and logical. It does require knowing cut-paste, but I think that 
> is pretty basic knowledge.
>
> Of course, part of obscurity relates to what we are used to. For a 
> non-programmer, everything is obscure. To someone who knows no regex, 
> just about any regex is obscure. etc. You're a brilliant programmer in 
> some ways, come up with clever solutions that I don't expect. But what 
> is obvious to you may be obscure to others. We might define "obscure" as 
> "hard for others to understand and maintain". The key word is "others". 
> For me, when I write something, I try to put myself in the shoes of 
> someone else, of average competency, looking at the code for the first 
> time, or in the shoes of myself looking at the code for the first time 
> in a year. By those criteria, I think the code is obscure.
>
> If you want to know specifics of why I think the code is obscure, I 
> could share that, but do not want to bog down the group. You could 
> contact me offline, or ask here if you prefer. I'm of two opinions. I 
> think code readability is very important, in almost all cases second in 
> importance only to correct operation, that much code is rather poorly 
> written, and that readability is a real thing that even can be measured. 
> OTOH, I am a little concerned about the partial "religious war" aspect 
> (X sucks!, Y rocks!, vi vs emacs, etc.), and that code readability is 
> such a huge subject that it might get a bit off topic.
>
> Daniel
>
> On 12/12/2015 12:11 PM, [sed-users] wrote:
>
>>> That is quite a feat you did! Of course, now it's very obscure, a huge negative, probably about as obscure as the perl solution. But at least you did it.
>>   When I posted the code, I tried to make it as modular as bash/sed would allow me to, thinking that it wouldn't be obscure. hmmm....
>>
>>   > This will ensure that the first line is not modified...
>>
>>> #!/bin/sh -u
>>> c=3;  # column to sed
>>> d=\;;  # csv delimiter character
>>> code="
>>>     ${c}{
>>>        s/.*/\L&/;
>>>        s/\<[a-z]/\u&/g;
>>>     }
>>>     H;1h;\$!d;
>>>     g;y/\\n/$d/;
>>   > "
>>
>>
>>
>>   > flag=
>>> while IFS= read -r Line; do
>>>     case $flag in '' ) printf '%s\n' "$Line"; flag=1; continue;; esac;
>>>     set -f;
>>>     IFS=$d; set X $Line; shift;
>>>     printf '%s\n' "$@" | sed -e "$code";
>>> done < input.csv
>>
>>
>> ---In [email protected], <dgoldman@...> wrote :
>>
>>   That is quite a feat you did! Of course, now it's very obscure, a huge
>>   negative, probably about as obscure as the perl solution. But at least
>>   you did it. The parameter-driven while-loop script would have to be
>>   fixed up not to operate on the first line, but I'm sure that could be
>>   done (I'm not suggesting you do it!). Anyway, as usual, there are
>>   several ways to do something, with advantages and disadvantages.
>>
>>   Daniel
>>
>>   On 12/12/2015 11:00 AM, [sed-users] wrote:
>>   > Of course the while-loop script can also be made parameter driven:
>>   >
>>   >
>>   > #!/bin/sh -u
>>   >
>>   >
>>   > c=3; # column to sed
>>   > d=\;; # csv delimiter
>>   >
>>   >
>>   > lc_code="$c!b;s/.*/\L&/;s/\<[a-z]/\u&/g"; # sed code to lowercase
>>   > pr_code="H;1h;\$!d;g;y/\\n/$d/"; # sed code to print line
>>   >
>>   >
>>   > while IFS= read -r Line; do
>>   > set -f;
>>   > IFS=$d; set X $Line; shift;
>>   > set X $(printf '%s\n' "$@" | sed -e "$lc_code"); shift;
>>   > echo "$@" | sed -e "$pr_code";
>>   > done < input.txt
>>   >
>>   >
>>   >
>>   > HTH
>>   >
>>   >
>>   > -Rakesh
>>   >
>>
>>
>>
>> [Non-text portions of this message have been removed]
>>
>>
>>
>> ------------------------------------
>> Posted by: [email protected]
>> ------------------------------------
>>
>
> ------------------------------------
> Posted by: Daniel Goldman <[email protected]>
> ------------------------------------
>




------------------------------------

------------------------------------

-- 

------------------------------------

Yahoo Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/sed-users/

<*> Your email settings:
    Individual Email | Traditional

<*> To change settings online go to:
    http://groups.yahoo.com/group/sed-users/join
    (Yahoo! ID required)

<*> To change settings via email:
    [email protected] 
    [email protected]

<*> To unsubscribe from this group, send an email to:
    [email protected]

<*> Your use of Yahoo Groups is subject to:
    https://info.yahoo.com/legal/us/yahoo/utos/terms/