I want to put serialized numbers on defined positions in a text file.
My idea is to use character patterns in the file, count up a variable and put them by using sed in the file. I tried this:
for number in 1 2 3 4 ; do
sed -ibak "s/var/$number" file.txt > file2.txt
done
(the arguments 1 2 3 ... are not the best solution, but I think, it should work)
With this code and tiny variations of it, I get different results, but no success.
I can cut/paste the pattern in the text, but it is always the last argument inserted (="3"). Why doesn´t sed take the iterated variable? (which is counted up, I tested it with echo).
The first iteration replaces var by 1, the next iteration replaces exactly the same var by 2, etc. - because you operate on the same input every time, and the pattern isn't dynamic.
It's not clear what you want to achieve, so it's hard to provide a working solution.
It might be easier to reach for Perl:
perl -pe 's/picvar/"pic" . ++$i/e'
Related
I am new to shell scripting, appreciate any help regarding below problem. I have tried to use sed and awk but unable to find a solution.
Problem: I have a fixed width file which has amount fields that need to be replaced with spaces/any special character like $ and the record length has to be maintained. The length of amount fields can vary.
For ex. if sample_file.txt has record length of 10 and there are two amount fields starting at 2 and 6 of length 3 and 5 in this file as below:
a234b67890
It has to be modified as:
a$$$b$$$$$
This is for unix server.
Edit:
Also the records can have numeric characters at other positions which shouldn't be updated. So considering the previous example, the updated input is:
a234b678901234567890
And new output should be:
a$$$b$$$$$1234567890
Try using
inp=a234b67890
echo $inp | sed 's/[0-9]/$/g'
# gives a$$$b$$$$$
The only requirement is that the input should always be of record_length as sed replaces the numbers with the special character.
Hope this helps.
I need help understanding a weird problem with sed, bash and a while loop.
MY data looks like this:
-File 1- CSV
account,hostnames,status,ipaddress,port,user,pass
-File 2- XML - This is a sample record set for two entries under one account
<accountname="account">
<cname="fqdn or simple name goes here">
<field="hostname">ahostname or ipv4 goes here</field>
<protocol>aprotocol</protocol>
<field="port">aportnumber</field>
<field="username">ausername</field>
<field="password">apassword</field>
</cname>
<cname="fqdn or simple name goes here">
<field="hostname">ahostname or ipv4 goes here</field>
<protocol>aprotocol</protocol>
<field="port">aportnumber</field>
<field="username">ausername</field>
<field="password">apassword</field>
</cname>
</accountname>
So far, I can add records in between the respective account holder from File1 to File2. But, if I need to remove records that no longer exists it does not work efficiently since it wipes other records from different accounts, ie it does not delete between a matched accountname.
I import from File 1 into File 2 with a while loop in my bash program:
-Bash Program excerpts-
//Read File in to F//
cat File 2 | while read F
do
//extract fields from F into variables
_vmname="$(echo $F |grep 'cname'| sed 's/<cname="//g' |sed 's/.\{2\}$//g')"
_account="$(echo $F | grep 'accountname' | sed 's/accountname="//g' |sed 's/.\{2\}$//g')"
// I then compare my File1 and look for stale records that are still in File2
if grep "$_vmname" File1 ;then
continue
else
// if not matched, delete between the respective accountname
sed -i '/'"$_account"'/,/<\/accountname>/ {/'"$_vmname"'/,/<\/cname>/d}' File2
If I manually declare _vmname and _account and run
sed -i '/'"$_account"'/,/<\/accountname>/ {/'"$_vmname"'/,/<\/cname>/d}' File2
It removes the stale records from File2. When I let my bash script run, it does not.
I think I have three problems:
Reading the variables for _vmname and _account name inside a loop makes it read numerous times. Any better way to do is appreciated.
I do not think the sed statement for matching these two patterns and then delete works like I want inside a while loop.
I may have a logic problem with my thought chain.
Any pointers, and please no awk, perl, lxml or python for this one.
Thanks!
and please no awk
I appreciate that you want to keep things simple, and I suppose awk seems more complicated than what you're doing. But I'd like to point out you have so far 3 grep and 4 sed invocations per line in the file, to process another file N times, once per line. That's O(mn) using the slowest method on the planet to read the file (a while loop). And it doesn't work.
I may have a logic problem with my thought chain.
I'm afraid we must allow for that possibility!
The right advice is to tackle XML with an XML parser, because XML is not a regular language and so can't be parsed with regular expressions. And that's really what you need here, because your program processes the whole XML document. You're not just plucking out bits and depending on incidental formatting artifacts; you want to add records that aren't there and remove those that "no longer exist". Apparently there is information in the XML document you need to preserve, else you would just produce it from the CSV. A parser would spoon-feed it to you.
The second-best advice is to use awk. I suppose you might try an approach like:
Process the CSV and produce the XML to be inserted.
In awk, first read the new input XML into an array keyed by cname, Then process the XML target once. For every CNAME, consult your array; if you find a match, insert your pre-constructed XML replacement (or modify the "paragraph" accordingly).
I'm not sure what the delete criteria are, so I don't know if it can be done in the same pass with step #2. If not, extract the salient information somehow. Maybe print a list of keys from each of the two files, and use comm(1) to produce a list of to-be-deleted. Then, similar to step #2, read in that list, and process the XML file one more time. Write anything you delete to stderr so you can keep track of what went missing, from what lines.
Any pointers
Whenever you find yourself processing the same file N times for N inputs, you know you're headed for trouble. One of the two inputs is always smaller, and that one can be put in some kind of array. cat file | while read is another warning signal, telling you use awk or any of a dozen obvious utilities that understand lines of text.
You posted your question on SO two weeks ago. I suspect no one answered it because you warned them away: preemptively saying, in effect, don't tell me to use good tools. I'm only here to suggest that you'll be more comfortable after you take off that straightjacket. Better tools, in this case, are the only right answer.
I need to write this solution as an AWK command. I am stuck on the last question:
Write a one line shell command that will count all lines in a file called "file.txt" that begin with a decimal number in parenthesis, containing a mix of both upper and lower case letters, and end with a period.
Example(s):
This is the format of lines we want to print. Lines that do not match this format should be skipped:
(10) This is a sample line from file.txt that your script should
count.
(117) And this is another line your script should count.
Lines like this, as well as other non-matching lines, should be skipped:
15 this line should not be printed
and this line should not be printed
Thanks in advance, I'm not really sure how to tackle this in one line.
This is not a homework solution service. But I think I can give a few pointers.
One idea would be to create a counter, and then print the result at the end:
awk '<COND> {c++} END {print c}'
I'm getting a bit confused by the terminology. First you claim that the lines should be counted, but in the examples, it says that those lines should be printed.
Now of course you could do something like this:
awk '<COND>' file.txt | wc -l
The first part will print out all lines that follow the condition, but the output will be parsed to wc -l which is a separate program that counts the number of lines.
Now as to what the condition <COND> should be, I leave to you. I strongly suggest that you google regular expressions and awk, it shouldn't be too hard.
I think the requirement is very clear
Write a one line shell command that will count all lines in a file called "file.txt" that begin with a decimal number in parenthesis, containing a mix of both upper and lower case letters, and end with a period.
1. begin with a decimal number in parenthesis
2. containing a mix of both upper and lower case letters
3. end with a period
check all three conditions. Note that in 2. it doesn't say "only" so you can have extra class of characters but it should have at least one uppercase and one lowercase character.
The example mixes concepts printing and counting, if part of the exercise it's very poorly worded or perhaps assumes that the counting will be done by wc by a piped output of a filtering script; regardless more attention should have been paid, especially for a student exercise.
Please comment if anything not clear and I'll add more details...
I am trying to write a bash script that uses sed to modify lines in a config file not containing a specific string. To illustrate by example, I could have ...
/some/file/path1 ipAddress1/subnetMask(rw,sync,no_root_squash)
/some/file/path2 ipAddress1/subnetMask(rw,sync,no_root_squash,anonuid=-1)
/some/file/path3 ipAddress2/subnetMask(rw,sync,no_root_squash,anonuid=0)
/some/file/path4 ipAddress2/subnetMask(rw,sync,no_root_squash,anongid=-1)
/some/file/path5 ipAddress2/subnetMask(rw,sync,no_root_squash,anonuid=-1,anongid=-1)
And I want every line's parenthetical list to be changed such that it contains strings anonuid=-1 and anongid=-1 within its parentheses ...
/some/file/path1 ipAddress1/subnetMask(rw,sync,no_root_squash,anonuid=-1,anongid=-1)
/some/file/path2 ipAddress1/subnetMask(rw,sync,no_root_squash,anonuid=-1,anongid=-1)
/some/file/path3 ipAddress2/subnetMask(rw,sync,no_root_squash,anonuid=-1,anongid=-1)
/some/file/path4 ipAddress2/subnetMask(rw,sync,no_root_squash,anongid=-1,anonuid=-1)
/some/file/path5 ipAddress2/subnetMask(rw,sync,no_root_squash,anonuid=-1,anongid=-1)
As can be seen from the example, both anonuid and anongid may already exist within the parentheses, but it is possible that the original parenthetical list has one string but not the other (lines 2, 3, and 4), the list has neither (line 1), the list has both already set properly (line 5), or even one or both of them are set incorrectly (line 3). When either anonuid or anongid is set to a value other than -1, it must be changed to the proper value of -1 (line 3).
What would be the best way to edit my config file using sed such that anonuid=-1 and anongid=-1 is contained in each line's parenthetical list, separated by a comma delimiter of course?
I think this does what you want:
sed -e '/anonuid/{s/anonuid=[-0-9]*/anonuid=-1/;b gid;};s/)$/,anonuid=-1)/;:gid;/anongid/{s/anongid=[-0-9]*/anongid=-1/;b;};s/)$/,anongid=-1)/'
Basically, it has two nearly identical parts with the first dealing with anonuid and the second anongid, each with a bit of logic to decide if it needs to replace or add the appropriate values. (It doesn't bother to check if the value is already correct, that would just complicate things while not changing the results.)
You can use sed to specify the lines you are interested in:
$ sed '/anonuid=..*,anongid=..*)$/!p' $file
The above will print (p) all lines that don't match the regular expression between the two slashes. I negated the expression by using the !. This way, you're not matching lines with both anaonuid and anongid in them.
Now, you can work on the non-matching lines and editing those with the sed s command:
$ sed '/anonuid=..*,anongid=..*)$/!s/from/to/`
The manipulation might be fairly complex, and you might be passing multiple sed commands to get everything just right.
However, if the string no_root_squash appear in each line you want to change, why not take the simple way out:
$ sed 's/no_root_squash.*$/no_root_squash,anonuid=-1,anongid=-1)/' $file
This is looking for that no_root_squash string, and replacing everything from that string to the end of the line with the text you want. Are there lines you are touching that don't need to be edited? Yes, but you're not really changing those lines. You're basically substituting /no_root_squash,anonuid=-1,anongid=-1) with the same /no_root_squash,anonuid=-1,anongid=-1).
This may be faster even though it's replacing text that doesn't need replacing because there's less processing going on. Plus, it's easier to understand and support in the future.
Response
Thanks David! Yeah I was considering going that route, but I didn't want to rely 100% on every line containing no_root_squash. My current config file only ends in that string, but I'm just not 100% sure that won't potentially be different in the field. Do you think there would be a way to change that so it just overwrites from the end of the last string not containing anonuid=-1 or anongid=-1 onward?
What can you guarantee will be in each line?
You might be able to do a capture group:
sed 's/\(sync,[^,)]*\).*/\1,anonuid=-1,anongid=-1)/' $file
The \(..\) is a capture group. It basically captures that portion of the matching regular expression, and then allows you to reuse it via the \1. I'm capturing from the word sync to a group of characters not including a comma or a closing parentheses. Then, I'm appending the capture group, a comma, and your anon uid and gid.
Will that work?
Maybe I am oversimplifying:
sed 's/anonuid=[-0-9]*[^)]//g;s/anongid=[-0-9]*[^)]//g;s/[)]/anonuid=-1,anongid=-1)/g' test.txt > test3.txt
This just drops any current instance of anonuid or anongid and adds the string
"anonuid=-1,anongid=-1" into the parentheses
Ok,first post..
So I have this assignment to decrypt cryptograms by hand,but I also wanted to automate the process a little if not all at least a few parts,so i browsed around and found some sed and awk one liners to do some things I wanted done,but not all i wanted/needed.
There are some websites that sort of do what I want, but I really want to just do it in bash for some reason,just because I want to understand it better and such :)
The script would take a filename as parameter and output another file such as solution$1 when done.
if [ -e "$PWD/$1" ]; then
echo "$1 exists"
else
echo "$1 doesnt exists"
fi
Would start the script to see if the file in param exists..
Then I found this one liner
sed -e "s/./\0\n/g" $1 | while read c;do echo -n "$c" ; done
Which works fine but I would need to have the number of occurences per letter, I really don't see how to do that.
Here is what I'm trying to achieve more or less http://25yearsofprogramming.com/fun/ciphers.htm for the counting unique letter occurences and such.
I then need to put all letters in lowercase.
After this I see the script doing theses things..
-a subscript that scans a dictionary file for certain pattern and size of words
the bigger words the better.
For example: let's say the solution is the word "apparel" and the crypted word is "zxxzgvk"
is there a regex way to express the pattern that compares those two words and lists the word "apparel" in a dictionnary file because "appa" and "zxxz" are similar patterns and "zxxzgvk" is of similar length with "apparel"
Can this be part done and is it realistic to view the problem like this or is this just far fetched ?
Another subscript who takes the found letters from the previous output word and that swap
letters in the cryptogram.
The swapped letters will be in uppercase to differentiate them over time.
I'll have to figure out then how to proceed to maybe rescan the new found words to see if they're found in a dictionnary file partly or fully as well,then swap more letters or not.
Did anyone see this problem in the past and tried to solve it with the patterns in words
like i described it,or is this just too complex ?
Should I log any of the swaps ?
Maybe just scan through all the crypted words and swap as I go along then do another sweep
with having for constraint in the first sweep to not change uppercase letters(actually to use them as more precise patterns..!)
Anyone did some similar script/program in another langage? If so which one? Maybe I can relate somehow :)
Maybe we can use your insight as to how you thought out your code.
I will happily include the cryptograms I have decoded and the one I have yet to decode :)
Again, the focus of my assignment is not to do this script but just to resolve the cryptograms. But doing scripts or at least trying to see how I would do this script does help me understand a little more how to think in terms of code. Feel free to point me in the right directions!
The cryptogram itself is based on simple alphabetic substitution.
I have done a pastebin here with the code to be :) http://pastebin.com/UEQDsbPk
In pseudocode the way I see it is :
call program with an input filename in param and optionally a second filename(dictionary)
verify the input file exists and isnt empty
read the file's content and echo it on screen
transform to lowercase
scan through the text and count the amount of each letter to do a frequency analysis
ask the user what langage is the text supposed to be (english default)
use the response to specify which letter frequencies to use as a baseline
swap letters corresponding to the frequency analysis in uppercase..
print the changed document on screen
ask the user to swap letters in the crypted text
if user had given a dictionary file as the second argument
then scan the cipher for words and find the bigger words
find words with a similar pattern (some letters repeating letters) in the dictionary file
list on screen the results if any
offer to swap the letters corresponding in the cipher
print modified cipher on screen
ask again to swap letters or find more similar words
More or less it the way I see the script structured.
Do you see anything that I should add,did i miss something?
I hope this revised version is more clear for everyone!
Tl,dr to be frank. To the only question i've found - the answer is yes:) Please split it to smaller tasks and we'll be happy to assist you - if you won't find the answer to these smaller questions before.
If you can put it out in pseudocode, it would be easier. There's all kinds of text-manipulating stuff in unix. The means to employ depend on how big are your texts. I believe they are not so big, or you would have used some compiled language.
For example the easy but costly gawk way to count frequences:
awk -F "" '{for(i=1;i<=NF;i++) freq[$i]++;}END{for(i in freq) printf("%c %d\n", i, freq[i]);}'
As for transliterating, there is tr utility. You can forge and then pass to it the actual strings in each case (that stands true for Caesar-like ciphers).
grep -o . inputfile | sort | uniq -c | sort -rn
Example:
$ echo 'aAAbbbBBBB123AB' | grep -o . | sort | uniq -c | sort -rn
5 B
3 b
3 A
1 a
1 3
1 2
1 1