I have a DCL script that creates a .txt file that looks something like this
something,somethingelse,00000004
somethingdifferent,somethingelse1,00000002
anotherline,line,00000015
I need to sort the file by the 3rd column highest to lowest
ex:
anotherline,line,00000015
something,somethingelse,00000004
somethingdifferent,somethingelse1,00000002
Is it best to use the sort command, if so everything i've seen required a position number, how can this be done if each line would have a different start position?
If sort is a bad way to handle this is there something else or can I somehow handle this while writing the lines to the file.
I've only been working with VMS/DCL for a few weeks now so i'm not fimilar with all of the commands yet.
Thanks!
As you already noticed, the VMS sort expects fields with a fixed start position within a record. You can not specify a field by a separator. If you want to use the VMS sort you have to make sure your third field starts at the same column, for all records. In other words, you have to pad preceding fields. If you have control on how the file is created, this may work for you. If you don't or you don't know how big the string in front of the sort field will be, this may not be a workaround. Maybe changing the order of the fields is an option.
On the other hand, you may find GNV installed on your system. Then you can try to use its sort, which is a GNU style sort. That is, $ mcr gnv$gnu:[bin]sort -t, -k3 -r x.txt may get you the wanted results.
VMS Sort is indeed not really equipped for this.
Reformatting as you did is about the only way.
If you so not have access to GNV sort on the OpenVMS system then perhaps you have, or can install PERL? Is is somewhat easier to install.
In perl there are of course many ways.
For example using an anonymous sort function ( $a is first arg, $b second; <> reads all input )
$ perl -e "print sort { 0+(split /,/,$b)[1] <=> 0+(split /,/,$a)[2]} <>" x.x
where the 0 + forces numeric evaluation. For (fixed length?) string compare use:
$ perl -e "print sort { (split /,/,$b)[2] cmp (split /,/,$a)[2]} <>" x.x
hth,
Hein.enter code here
Related
I have a CSV file--let's call it search.csv--with three columns. For each row, the first column contains a different string. As an example (punctuation of the strings is intentional):
Col 1,Col 2,Col 3
string1,valueA,stringAlpha
string 2,valueB,stringBeta
string'3,valueC,stringGamma
I also have a set of directories contained within one overarching parent directory, each of which have a subdirectory we'll call source, such that the path to source would look like this: ~/parentDirectory/directoryA/source
What I would like to do is search the source subdirectories for any occurrences--in any file--of each of the strings in Col 1 of search.csv. Some of these strings will need to be manually edited, while others can be categorically replaced. I run the following command . . .
awk -F "," '{print $1}' search.csv | xargs -I# grep -Frli # ~/parentDirectory/*/source/*
What I would want is a list of files that match the criteria described above.
My awk call gets a few hits, followed by xargs: unterminated quote. There are some single quotes in some of the strings in the first column that I suspect may be the problem. The larger issue, however, is that when I did a sanity check on the results I got (which seemed far too few to be right), there was a vast discrepancy. I ran the following:
ag -l "searchTerm" ~/parentDirectory
Where searchTerm is a substring of many (but not all) of the strings in the first column of search.csv. In contrast to my above awk-based approach which returned 11 files before throwing an error, ag found 154 files containing that particular substring.
Additionally, my current approach is too low-resolution even if it didn't error out, in that it wouldn't distinguish between which results are for which strings, which would be key to selectively auto-replacing certain strings. Am I mistaken in thinking this should be doable entirely in awk? Any advice would be much appreciated.
I am trying to parse some logs to gain the user agent and account id per line. I have already managed to pull the user agent and a string which contains the account id all on the same line.
The next step is to extract the account id from its longer string. I thought this would be fairly simple as I will know the start of the string and there are / slashes for the delimiter but the user agent also contains slashes and have varied number of fields.
The log file currently looks something like the following example but there are hundreds to thousands of lines to parse. Luckily I am working off a partition with plenty of space to spare.
USER_AGENT_PART ACCOUNT_ID_Part_/plus/path/to/stuff/they/access
some user agent/1.3 KnownString1_32d4-56e-009f98/some/stuff/here
user/agent KnownString1_12d3-345e-4c534/more/stuff/here
User/Agent cURL/1.5.0 KnownString2_12d34e56/stuff/things/stuff/stuff
one/User Agent/2.0 KnownString1_12d3_456e_7g8/more/random/stuff/stuff
So the goal is to keep the user agent part and the account id part and drop the path of the stuff they are accessing in the last string. But I can't use / or spaces as general delimiters because many user agents have / and various amounts of spaces in their name.
Also, the different types of user agents is way more than this little sample I have here. There are anywhere from 25 - 50 distinct types depending on the log. So it doesn't seem worth it to target the user agent and try to exclude it.
It seems the logical way to start is by targeting the part of the account ID which is a known string (KnownString1 or KnownString2) and grab everything from there (which is unknown numbers and letters with dashes) up until the first / of that account string.
Then I would delete the first / (In the account ID string) and everything after. I expect I will need to do this in two passes to utilize the two known parts of the user IDs.
This seemed like it would be easy but I just can't wrap my head around how to start targeting that last string. I don't even have a good example of something that is close to working because I don't know how to target the last string by delimiters without catching the same delimiters in the user agent part.
Any ideas?
Edit: Every line will have an account id that starts with one of two common KnownString_ in it but then is followed by a series of unknown digits and dashes until it gets to the first /. So I don't need to search for lines containing that before targeting the string.
Edit2: My original examples of the Account ID did not reflect there were letters mixed in with the numbers.
Edit3: Thanks to the responses from oguz ismail and kesubagu I was able to solve this using egrep. Looks like I was trying to make things more complicated than they were. I also realized I need to revisit grep as its capable of doing far more than what I tend to use it for.
This is what I ended up using which worked in one pass:
egrep -o ".+(KnownString1|KnownString2)_[^/]+" logfile > logfile2
Using grep:
$ grep -o '.*KnownString[^/]*' file
some user agent/1.3 KnownString1_32d4-56e-009f98
user/agent KnownString1_12d3-345e-4c534
User/Agent cURL/1.5.0 KnownString2_12d34e56
one/User Agent/2.0 KnownString1_12d3_456e_7g8
.* matches everything before KnownString, and [^/]* matches everything after KnownString until the first /.
You can use egrep with the -o option which will only output the part of that matches the provided regex, so you could do something like this
cat test | egrep -o ".+(KnownString1|KnownString2)_[_0-9-]+"
where the test file contains the input you've given, the output in this case was
some user agent/1.3 KnownString1_324-56-00998
user/agent KnownString1_123-345-4534
User/Agent cURL/1.5.0 KnownString2_123456
one/User Agent/2.0 KnownString1_123_456_78
I am running a script that outputs data.
I am specifically trying to extract one number. However, each time I run the script and get the output file, the position of the number I am interested in will be in a different position (due to the log nature of the output file).
I have tried several awk, sed, grep commands but I can't get any to work as many of them rely on the position of the word or number remaining constant.
This is what I am dealing, with. The value I require is the bold one:
Energy initial, next-to-last, final =
-5.96306582435 -5.96306582435 -5.96349956298
You can try
awk '{print $(i++%3+6)}' infile
I am trying out a classic format string vulnerability. I want to know how exactly the following format string works:
"%NNN$hhn" where 'N' is any number.
E.g: printf("%144$hhn",....);
How does it work and how do I use this to overwrite any address I want with arbitrary value?
Thanks and Regards,
Hrishikesh Murali
It's a POSIX extension (not found in C99) which will simply allow you to select which argument from the argument list to use for the source of the data.
With regular printf, each % format specifier grabs the current argument from the list and advances the "pointer" to the next one. That means if you want to print a single value in two different ways, you need something like:
printf ("%c %d\n", chVal, chVal);
By using positional specifiers, you can do this as:
printf ("%1$c %1$d\n", chVal);
because both format strings will use the first argument as their source.
Another example on the wikipedia page is:
printf ("%2$d %2$#x; %1$d %1$#x",16,17);
which will give you the output:
17 0x11; 16 0x10
It basically allows you to disconnect the order of the format specifiers from the provided values, letting you bounce around the argument list in any way you want, using the values over and over again, in any arbitrary order.
Now whether you can use this as an user attack vector, I'm doubtful, since it only adds a means for the programmer to change the source of the data, not where the data is sent to.
It's no less secure than the regular style printf and I can see no real vulnerabilities unless you have the power to change the format string somehow. But, if you could do that, the regular printf would also be wide open to abuse.
script(1) is a tool for keeping a record of an interactive terminal session; by default it writes to the file transcript. My problem is that I use ksh93, which has readline features, and so the transcript is mucked up with all sorts of terminal escape sequences and it can be very difficult to reconstruct the command that was actually executed. Not to mention the stray ^M's and the like.
I'm looking for a tool that will read a transcript file written by script, remove all the junk, and reconstruct what the shell thought it was executing, so I have something that shows $PS1 and the commands actually executed. Failing that, I'm looking for suggestions on how to write such a tool, ideally using knowledge from the terminfo database, or failing that, just using ANSI escape sequences.
A cheat that looks in shell history, as long as it really really works, would also be acceptable.
Doesn't cat/more work by default for browsing the transcript? Do you intend to create a script out of the commands actually executed (which in my experience can be dangerous)?
Anyway, 3 years without an answer, so I will give it a shot with an incomplete solution. If your are only interested in the commands actually typed, remove the non-printable characters, then replace PS1' with something readable and unique, and grep for that unique string. Like this:
$ sed -i 's/[^[:print:]]//g' transcript
$ sed 's/]0;cartman#southpark: ~cartman#southpark:~/CARTMAN/g' transcript | grep CARTMAN
Explanation: After first sed, PS1' can be taken from one of the first few lines of the transcript file, as is -- PS1' is different from PS1 -- and can be modified with a unique readable string ("CARTMAN" here). Note that the dollar sign at the end of the prompt was left out intentionally.
In the few examples that I tried, this didn't solve everything but took care of most issues.
This is essentially the same question asked recently in Can I programmatically “burn in” ANSI control codes to a file using unix utils? -- removing all nonprinting characters will not fix
embedded escape sequences
backspace/overstriking for underlining
use of carriage-returns for overstriking