Substitue single-digit, two-digit, and 3-digit numbers with text using sed

dmason165 · 08-05-2009, 04:40 PM

Hi,

I'm trying to write a sed script that will evaluate a file with exit codes, and substitutes the numerical exit codes (which are single-, two-, or three-digit numbers) for their description.

The process goes like this:

I have a script that obtains an exit code/status for backups and dumps the output in a file. We'll call the file bkp_status. Entriess in bkp_status are in this format:

server1,exit_code
server2,exit_code
server3,exit_code
.
.
.

I have tried for a couple days now to pipe this file into a sed script that will substitute the exit_code for its description, and generate output as follows:

server1,exit_code,(exit_code_description)
server2,exit_code,(exit_code_description)
server3,exit_code,(exit_code_description)
.
.
.

The problem I keep running into is that sed will not evaluate two- or three-digit numbers as a single number. In other words, this input:

server1,86

piped through these sed commands:

s/,6/,6,(the backup failed to back up the requested files)/
s/,8/,8,(unable to determine the status of rbak)/
s/,86/,86,(media position error)/

returns this:

server1,8,(unable to determine the status of rbak)6

I have tried surrounding the numbers in brackets, parens, single-quotes, double-quotes, escaping them, all to no avail.

Any suggestions?

Thanks in advance.

Berhanie · 08-05-2009, 05:11 PM

better to match the end of the line with '$':

Code:

s/,6$/,6,(the backup failed to back up the requested files)/
s/,8$/,8,(unable to determine the status of rbak)/
s/,86$/,86,(media position error)/

pixellany · 08-05-2009, 06:29 PM

SED has no capacity to evaluate numbers---it works strictly on strings. Before you start piping commands together, test them one at a time to make sure they are doing what you need.

Really good SED tutorial here:
http://www.grymoire.com/Unix/Sed.html

joeBuffer · 08-05-2009, 07:45 PM

Why not use awk? Something like:

Code:

BEGIN {
	FS=","
	OFS=","

	# ecd - exit code description
	ecd1 = "exit code #1"
	ecd2 = "exit code #2"
	ecd3 = "exit code #3"
}

$2 ~ /exit_code1/ {
	print $0 , ecd1
}

$2 ~ /exit_code2/ {
	print $0 , ecd2
}

$2 ~ /exit_code3/ {
	print $0 , ecd3
}

in your.awk, then use with:

Code:

awk -f your.awk bkp_status

joeBuffer · 08-05-2009, 07:48 PM

Of course, this is assuming your file is layed out like what you're showing, only written differently.
For example:

Code:

server1,exit_code1
server2,exit_code2
server3,exit_code1
server4,exit_code3

the output is:

Code:

server1,exit_code1,exit code #1
server2,exit_code2,exit code #2
server3,exit_code1,exit code #1
server4,exit_code3,exit code #3

I added the numbers to the end of the exit codes in bkp_status, to more accurately represent what you're file looks like.

joeBuffer · 08-05-2009, 07:51 PM

It will work the same with a numerical exit status in bkp_status as it will with what I've used for the example.

joeBuffer · 08-05-2009, 07:58 PM

Damn, I posted it wrong at first. I just added the //'s around the exit_status# parts. You need those for a regular expression.

pixellany · 08-05-2009, 08:05 PM

joe;
It's better to edit (or add to one post than to keep adding new ones---but please don't lose your enthusiasm for helping people...

ghostdog74 · 08-05-2009, 08:20 PM

use awk instead of sed....

Code:

awk 'BEGIN{
    code["86"]="eighty6"
    code["87"]="eighty7"
    code["89"]="eighty9"
    OFS=FS=","
}
{
    print $1,$2,code[$2]
}' file

joeBuffer · 08-05-2009, 08:27 PM

The first three posts were really how I meant them, I thought they were sort of separate ... sorry about that.
Only the fourth one I added to draw more attention to the fact that I left out the //'s, just in case they maybe saw it quickly and tried it and had it do the wrong thing.

joeBuffer · 08-05-2009, 08:30 PM

That's basically what I just posted, ghostdog, only shorter. It would be better for space. I also wrote in my post "something like:" because I know it can be made with fewer lines, and maybe something else could come up that the original poster wants to do.

dmason165 · 08-05-2009, 08:59 PM

Thanks Berhanie, joeBuffer, and ghostdog74 for your posts!! VERY much appreciated. I will test them later tonight and report back with my findings.

pixellany, thanks for the link to grymoire.com. I've referenced it many times before for reminders here-and-there; it's one of the more popular and better-written tutorials on the Web. And FYI, I'm at the part in my script where the pipe didn't work, so I came here for assistance. As a moderator, and somewhat of a forum role-model, you should take care with your tone and suggestions. It may not be what you intended, but your post comes across like you're advising someone who has no clue what they're doing; such a post can be discouraging when it's directed toward someone who doesn't or offensive when it's directed toward someone who does.

Thanks again everyone!
~D

pixellany · 08-07-2009, 08:22 AM

Quote:

Originally Posted by dmason165

Thanks Berhanie, joeBuffer, and ghostdog74 for your posts!! VERY much appreciated. I will test them later tonight and report back with my findings.

pixellany, thanks for the link to grymoire.com. I've referenced it many times before for reminders here-and-there; it's one of the more popular and better-written tutorials on the Web. And FYI, I'm at the part in my script where the pipe didn't work, so I came here for assistance. As a moderator, and somewhat of a forum role-model, you should take care with your tone and suggestions. It may not be what you intended, but your post comes across like you're advising someone who has no clue what they're doing; such a post can be discouraging when it's directed toward someone who doesn't or offensive when it's directed toward someone who does.

Thanks again everyone!
~D

I am sorry, but my comments were:
1) a matter of fact statement about how SED does not evaluate numbers, and
2) a suggestion on how to unravel what was being attempted.

If you stick around here for a while, you'll note that many members have time available only in fragments-----you'll quite often see a terse suggestion or comment with more in-depth follow-up later.

Regardless, I'm glad to see you are getting somewhere and that you have the courtesy to thank those that help you.

rn_ · 08-07-2009, 10:38 AM

Try modifying your s commands like so:

Code:

s/,\<6\>/,6,(the backup failed to back up the requested files)/
s/,\<8\>/,8,(unable to determine the status of rbak)/
s/,\<86\>/,86,(media position error)/

HTH.
-RN.