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When I read about Unix tools there seems to be a lot of overlap between
them, like

shells
awk
sed
Perl
Python
C
tcl/tk
Java
Lisp

What's a beginner to do that can only learn one at a time? If I learn
Perl, is there any reason at all to look at awk and sed? What does Python
do that Perl doesn't? I like the thought of the C/tcl/tk combination,
e.g. a simple way to put a graphical interface on my C apps, or so the
legends go, but has Java made that obsolete? What does anyone use Lisp
for?

Please share some opinions.


--
"Let us learn to dream, gentlemen, then perhaps we shall find the
truth... But let us beware of publishing our dreams before they have been
put to the proof by the waking understanding." -- Friedrich August Kekulé

On Fri, 24 Oct 2003 01:22:25 +0000 (UTC), Gregory L. Hansen <glhansen@steel.ucs.indiana.edu> wrote:
>
>
>
> When I read about Unix tools there seems to be a lot of overlap between
> them, like
>
> shells
> awk
> sed
> Perl
> Python
> C
> tcl/tk
> Java
> Lisp
>
> What's a beginner to do that can only learn one at a time? If I learn
> Perl, is there any reason at all to look at awk and sed? What does Python
> do that Perl doesn't? I like the thought of the C/tcl/tk combination,
> e.g. a simple way to put a graphical interface on my C apps, or so the
> legends go, but has Java made that obsolete? What does anyone use Lisp
> for?
>
> Please share some opinions.
>
>

The shell is a command interpreter which stands between you and the kernel.

Sed is an editor, the rest are programming languages with various focusses,
or, in the case of C, a general language.

The shell includes a high-level and immensely practical programming language,
and you would be very wise to learn an sh-compatible shell like bash or zsh,
before tackling any of the other languages.

And then, once you have a handle on 'sh', skip the rest and go for broke:
learn C, (which most of the others are written in :-)

Learn the stream editor sed because it is very, very useful.

--
Alan C
Post validation at http://tinyurl.com/rv0y

In article <bn9ush$j0e$3@hood.uits.indiana.edu>,
Gregory L. Hansen <glhansen@steel.ucs.indiana.edu> wrote:
>
>When I read about Unix tools there seems to be a lot of overlap between
>them, like
>
> shells
> awk
> sed
> Perl
> Python
> C
> tcl/tk
> Java
> Lisp
>
>What's a beginner to do that can only learn one at a time? If I learn
>Perl, is there any reason at all to look at awk and sed? What does Python
>do that Perl doesn't? I like the thought of the C/tcl/tk combination,
>e.g. a simple way to put a graphical interface on my C apps, or so the
>legends go, but has Java made that obsolete? What does anyone use Lisp
>for?
>
>Please share some opinions.

Learn a shell first, choose the one that you can get someone to
answer your questions one on one in person. Best is some Bourne
like shell which will be good for scripting and interactive use.

Next learn your basic unix commands as are found in "Unix in a
Nutshell." This includes awk and sed.

Then decide if you want to learn C, then Perl and the other stuff.

Perl is too cryptic to learn initially, and awk and sed are much
more straughtforward, as is C (C++ is harder to master).

So much for some initial thoughts.


Chuck Demas

--
Eat Healthy | _ _ | Nothing would be done at all,
Stay Fit | @ @ | If a man waited to do it so well,
Die Anyway | v | That no one could find fault with it.
demas@theworld.com | \___/ | http://world.std.com/~cpd

Alan Connor <zzzzzz@xxx.yyy> wrote in message news:<JH%lb.3593$wc3.2929@newsread3.news.pas.earth link.net>...
> On Fri, 24 Oct 2003 01:22:25 +0000 (UTC), Gregory L. Hansen <glhansen@steel.ucs.indiana.edu> wrote:
> >
> >
> >
> > When I read about Unix tools there seems to be a lot of overlap between
> > them, like
> >
> > shells
> > awk
> > sed
> > Perl
> > Python
> > C
> > tcl/tk
> > Java
> > Lisp
> >
> > What's a beginner to do that can only learn one at a time? If I learn
> > Perl, is there any reason at all to look at awk and sed? What does Python
> > do that Perl doesn't? I like the thought of the C/tcl/tk combination,
> > e.g. a simple way to put a graphical interface on my C apps, or so the
> > legends go, but has Java made that obsolete? What does anyone use Lisp
> > for?
> >
> > Please share some opinions.
> >
> >
>
> The shell is a command interpreter which stands between you and the kernel.
>
> Sed is an editor, the rest are programming languages with various focusses,
> or, in the case of C, a general language.
>
> The shell includes a high-level and immensely practical programming language,
> and you would be very wise to learn an sh-compatible shell like bash or zsh,
> before tackling any of the other languages.
>
> And then, once you have a handle on 'sh', skip the rest and go for broke:
> learn C, (which most of the others are written in :-)
>
> Learn the stream editor sed because it is very, very useful.


The "Advanced Bash Scripting Guide" available at tldp.org is
worth reading. It has many commented scripts.

Walt R.

On 23 Oct 2003 21:46:42 -0700, Walt R <wmreinemer@tns.net> wrote:
>
>
> Alan Connor <zzzzzz@xxx.yyy> wrote in message news:<JH%lb.3593$wc3.2929@newsread3.news.pas.earth link.net>...
>> On Fri, 24 Oct 2003 01:22:25 +0000 (UTC), Gregory L. Hansen <glhansen@steel.ucs.indiana.edu> wrote:
>> >
>> >
>> >
>> > When I read about Unix tools there seems to be a lot of overlap between
>> > them, like
>> >
>> > shells
>> > awk
>> > sed
>> > Perl
>> > Python
>> > C
>> > tcl/tk
>> > Java
>> > Lisp
>> >
>> > What's a beginner to do that can only learn one at a time? If I learn
>> > Perl, is there any reason at all to look at awk and sed? What does Python
>> > do that Perl doesn't? I like the thought of the C/tcl/tk combination,
>> > e.g. a simple way to put a graphical interface on my C apps, or so the
>> > legends go, but has Java made that obsolete? What does anyone use Lisp
>> > for?
>> >
>> > Please share some opinions.
>> >
>> >
>>
>> The shell is a command interpreter which stands between you and the kernel.
>>
>> Sed is an editor, the rest are programming languages with various focusses,
>> or, in the case of C, a general language.
>>
>> The shell includes a high-level and immensely practical programming language,
>> and you would be very wise to learn an sh-compatible shell like bash or zsh,
>> before tackling any of the other languages.
>>
>> And then, once you have a handle on 'sh', skip the rest and go for broke:
>> learn C, (which most of the others are written in :-)
>>
>> Learn the stream editor sed because it is very, very useful.
>
>
> The "Advanced Bash Scripting Guide" available at tldp.org is
> worth reading. It has many commented scripts.
>
> Walt R.

A great document, but starting with one of the free on-line tutorials, and
asking the folks at comp.unix.shell to help you out when you get stuck, is
a very good idea.

--
Alan C
Post validation at http://tinyurl.com/rv0y

glhansen@steel.ucs.indiana.edu (Gregory L. Hansen) writes:

> When I read about Unix tools there seems to be a lot of overlap between
> them, like
>
> shells awk sed Perl Python C tcl/tk Java Lisp
>
> What's a beginner to do that can only learn one at a time?

Get a book that shows you a walk around all of these (particularly the
first half; I'm sure there are some `unix programming' type things out
there).

> If I learn Perl, is there any reason at all to look at awk and sed?

Yes. They're smaller and quicker; I'd prefer to pipe something through
awk '{print $3}'
rather than the corresponding Perl.

> What does Python do that Perl doesn't?

Has a totally different OO model, a different syntax, ... read
<http://www.python.org/>, there are some docst there (somewhere!).

> I like the thought of the C/tcl/tk combination, e.g. a simple way to put
> a graphical interface on my C apps, or so the legends go, but has Java
> made that obsolete?

It's one way to go; the most canonical Java systems have dubious licensing
constraints and are not well ported to all OSs.

If you're into scripting, you might want to do a language comparison
involving ruby, python, tcl and perl; there's no harm in knowing (for
example) how to generate an image-thumnail directory listing in each of
them, or something similar.

> What does anyone use Lisp for?

Well, I use the Scheme dialect for a few things - anything where I think a
clean functional approach will benefit. See <http://www.lisp.org>,
<http://www.schemers.org/>. And, of course, my "editor" is emacs, which is
written in emacs lisp...

~Tim
--
A big sky above me, |piglet@stirfried.vegetable.org.uk
West winds blow. |http://spodzone.org.uk/

In article <bna4r2$e99$1@pcls3.std.com>,
Charles Demas <demas@TheWorld.com> wrote:
>In article <bn9ush$j0e$3@hood.uits.indiana.edu>,
>Gregory L. Hansen <glhansen@steel.ucs.indiana.edu> wrote:
>>
>>When I read about Unix tools there seems to be a lot of overlap between
>>them, like
>>
>> shells
>> awk
>> sed
>> Perl
>> Python
>> C
>> tcl/tk
>> Java
>> Lisp
>>
>>What's a beginner to do that can only learn one at a time? If I learn
>>Perl, is there any reason at all to look at awk and sed? What does Python
>>do that Perl doesn't? I like the thought of the C/tcl/tk combination,
>>e.g. a simple way to put a graphical interface on my C apps, or so the
>>legends go, but has Java made that obsolete? What does anyone use Lisp
>>for?
>>
>>Please share some opinions.
>
>Learn a shell first, choose the one that you can get someone to
>answer your questions one on one in person. Best is some Bourne
>like shell which will be good for scripting and interactive use.
>
>Next learn your basic unix commands as are found in "Unix in a
>Nutshell." This includes awk and sed.
>
>Then decide if you want to learn C, then Perl and the other stuff.
>
>Perl is too cryptic to learn initially, and awk and sed are much
>more straughtforward, as is C (C++ is harder to master).
>
>So much for some initial thoughts.

I actually have some familiarity with shells, less now than I did through
disuse of most features besides starting up programs and sometimes piping
them around. And I know C and C++, but I haven't used them much in a Unix
context. And I have a fat Unix book that describes some of that stuff,
like sed and awk but not Perl, that I plan to go through when I get Linux
in my home. But Perl has been described as doing more than sed and awk
together, removing the need to pipe things around between the two and the
shell, so I wondered whether I even need to care about them. One thing I
have in mind is a fairly elaborate e-mail filter that can keep tallies,
filter on attachments, send notifications of spam deletions, recognize
spoofed words like pe.n!s, which are things that slocal on my Sun shell
account can't do, so off-hand Perl seemed like the one to use, based
strictly on what I've read about it but no knowledge of it.

At least one person likes Python for scientific programming, but I don't
know if that does things that Perl doesn't, or makes the job especially
easier than C or Fortran would.

--
"Let us learn to dream, gentlemen, then perhaps we shall find the
truth... But let us beware of publishing our dreams before they have been
put to the proof by the waking understanding." -- Friedrich August Kekulé

On 10/24/2003 9:12 AM, Gregory L. Hansen wrote:
<snip>
> And I have a fat Unix book that describes some of that stuff,
> like sed and awk but not Perl, that I plan to go through when I get Linux

You could download cygwin (www.cygwin.org) while you're waiting...

> But Perl has been described as doing more than sed and awk
> together, removing the need to pipe things around between the two

You never need to do pipe things between sed and awk since awk can do anything
sed can do. In the context of sed/awk solutions: for small things that sed can
do easily, only use sed, and for the rest only use awk.

and the
> shell, so I wondered whether I even need to care about them. One thing I
> have in mind is a fairly elaborate e-mail filter that can keep tallies,
> filter on attachments, send notifications of spam deletions, recognize
> spoofed words like pe.n!s, which are things that slocal on my Sun shell
> account can't do, so off-hand Perl seemed like the one to use, based
> strictly on what I've read about it but no knowledge of it.

No, procmail, formail and/or spamassasin are some tools for that job.

Ed.

In article <3F99414A.5070803@Lucent.com>,
Ed Morton <mortonAVOIDINGSPAM@Lucent.com> wrote:
>
>
>On 10/24/2003 9:12 AM, Gregory L. Hansen wrote:
><snip>
>> And I have a fat Unix book that describes some of that stuff,
>> like sed and awk but not Perl, that I plan to go through when I get Linux
>
>You could download cygwin (www.cygwin.org) while you're waiting...

A cygmac would actually be more useful to me.

>
>> But Perl has been described as doing more than sed and awk
>> together, removing the need to pipe things around between the two
>
>You never need to do pipe things between sed and awk since awk can do anything
>sed can do. In the context of sed/awk solutions: for small things that sed can
>do easily, only use sed, and for the rest only use awk.

Okay.

>
> and the
>> shell, so I wondered whether I even need to care about them. One thing I
>> have in mind is a fairly elaborate e-mail filter that can keep tallies,
>> filter on attachments, send notifications of spam deletions, recognize
>> spoofed words like pe.n!s, which are things that slocal on my Sun shell
>> account can't do, so off-hand Perl seemed like the one to use, based
>> strictly on what I've read about it but no knowledge of it.
>
>No, procmail, formail and/or spamassasin are some tools for that job.

None of those exist on my Sun account, only slocal, and I don't have a lot
of disk space there. And rolling my own would likely be more
instructional, so I thought I'd give it a try.

--
"Let us learn to dream, gentlemen, then perhaps we shall find the
truth... But let us beware of publishing our dreams before they have been
put to the proof by the waking understanding." -- Friedrich August Kekulé

2003/10/24, 10:12(-05), Ed Morton:
[...]
> You never need to do pipe things between sed and awk since awk
> can do anything sed can do.
[...]

Not always. Even GNU awk can't do easily things that sed can
do in one line.

sed 's/\(.\)\1/2\1/3'

replaces the third occurrence of two consecutive same chars 'X'
with "2X" (may not work with some old seds).

The same in awk:

awk '{
line=$0; l=length; n=3; o=""
for (i=1;i<=l;i++) {
c=substr($0,i,1);
if (c == o) {
if (!--n) {
line=substr($0,1,i-2) "2" substr($0, i)
break
}
o=""
} else
o=c
}
print line}'


gawk '{print gensub(/(.)\1/,"2\\1",3)}'

doesn't work.

There's no equivalent for 'y' in awk.

--
Stéphane ["Stephane.Chazelas" at "free.fr"]