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Using the 9base port in {Net,Free}BSD, it appears that Plan 9's sed

1. restricts the max number of sed commands and thereby the length of sed scripts

2. does not recognise the \nn flag where nn...

I had another go at this without using xxd.

This version uses only sh builtins, sed, jot/seq and dc.

Not thoroughly tested, but seems to work.

Handling unicode too would be useful.


#...

The challenge:

Decode URL's, i.e. convert %HEX to the corresponding special characters, using only UNIX base utilities, and without having to type out each special character.

I have an...

It's the standard FreeBSD /bin/sh, i.e. ash.

No doubt the answer lies in the source code. Still being a C noob, I gave up. But I may return to this since it has my curiousity.

I believe the...

I like it.
But still I get nothing.
I can't figure out where the output is going.

I can't seem to filter the output of jobs -l (/bin/sh).
Never had a problem with this on NetBSD.
Really strange.
It must be something really obvious I'm over looking.
What could it be?


jobs...

[deleted]

JG: Would you believe I also omitted a typdef that did just that? For the kelly example, I took the struct out of a context where I still don't fully understand the context. Hence the omissions.
...

JohnGraham: Would const be useful if the struct was as follows?


const struct kelly {
/* ... */
void (*lg)(int);
} friends[] = {
/* ... */
};


Shamrock: Many thanks.

The "kelly"...

In a well-known book on the C language, there is an example of an efficient method for using a struct member as an argument to a function. (I'm a C noob, but I believe the correct terminology might...

That's exactly what I was looking for. I wanted to use case..esac.

Many thanks, Scrutinizer.

I once read something that suggested as jobs get larger, case..esac is faster than if..then. ...

Testing for the presence/absence of a pattern in a file, using /bin/sh:


while read a;
do
b="${a##*pattern*}";
[ "$b" = "" ];
done < file


This returns 0 if there's a match. That signal...

Found via the infamous sed one-liners file.



# delete last 2 lines of file

sed 'N;$!P;$!D;$d' < file
printf "This is the new line 4\n"
printf "\n"



---------- Post updated at 08:36...

The file is repeating blocks of text separated by a blank line. Some of the lines are unique.

e.g.:

This is unique line
This is line 2
This is line 3
This is line 4

This is unique line...

Disclaimer: This is just a rainy day experiment. There is no expected "goal" other than to understand UNIX better.

After reading about fork and exec, my understanding is that forking, as the...

Would you believe it was simply a matter of me forgetting to use the -n operand with sed?

I tried to tag this post for deletion seconds later when I realised it. But I guess that didn't work.
...

Here's the input:

alpha, numeric or alphanumeric string ("line 1 string")
numeric string ("line 2 string")
numeric string ("line 3 string")
numeric string ("line 4 string")
...

where
-...

Let me rephrase.

"bigfile" is actually not a file, it's a stream of bytes from the network.

What splitting to stdout means is that splitting does not require 2X the file size, i.e. bigfile +...

I want to split big files based on a pattern to stdout.

Although csplit works well for me splitting the output into separate files (e.g. xx00, xx01, xx02, ...), the following is not working as...

Thanks.

This works great. But the new status is not immediately reflected in the jobs -l output.

Can I get the status to update with another signal?

Certain events seem to trigger an...

Is there a way to suspend (TSTP?) a job that is running in the background, _without_ first bringing it to the foreground and inputting Ctrl-Z from the keyboard?

IOW, something similar to issuing...

Many, many thanks agama!

It all works now.

(Your first solution for the single quote actually works too. I hastily overlooked your single quotes around the forward slash.)

Great stuff. ...

I see an escaped t in your sed command. That tells me you're using a sed that supports more than mine does (e.g., symbols for tabs, newlines, etc. plus octal and hex, if it's the GNU version).
...

The task: remove undesirable characters from filenames.

Restrictions: Must use basic RE, base utilities (non-GNU) and /bin/sh (ash). No ksh, zsh, perl, etc.

Below is what I've come up with. It...

Excellent! I've learnt something new! Cheers! :)