I have a string in different ranges :
WATSON_AJAY_AB04_DOTHING.data
WATSON_NAVNEET_CK4_DOTHING.data
WATSON_PRASHANTH_KJ56_DOTHING.data
WATSON_ABHINAV_KD323_DOTHING.data
On these above string how can I extract
AB04,CK4,KJ56,KD323
in Unix?
echo "$string" | cut -d'_' -f3
You could use sed or grep for this task. But since the string is so simple, I dont think you will need to.
One method is to use the bash 'cut' command. Below is an example directly on the BASH shell/command line:
jimm#pi$ string='WATSON_AJAY_AB04_DOTHING.data'
jimm#pi$ cut -d '_' -f 3 <<< "$string"
AB04 <-- outputs the result directly
(edit: of course Lucas' answer above is also a quick 'one-liner' that does the same thing as above - he beat me to it) :)
The cut will take an _ character as the delimiter (the -d '_' part), then display the 3rd slice of the string (the -f 3 part).
Or, if you want to output that 3rd slice from a list of content (using your list above), you can write a simple BASH script.
First, save the lines above ('WATSON...etc') into something like text.txt. Then open up your favorite text editor and type:
#!/bin/sh
cut -d '_' -f 3 < $1
Save that script to some useful name like slice.sh, and make sure it is executable with something like chmod 775 slice.sh.
Then at the command line you can execute the script against your text file, and immediately get an output of those parts of the file you want (in this case the third set of text, separated by the _ character):
$ ./slice.sh text.txt
AB04
CK4
KJ56
KD323
Hope that helps! Bear in mind that the commands above may vary a bit, depending on the flavor of *nix you are using, but it should at least point you in the right direction.
Related
I'm searching through text files using grep and sed commands and I also want the file names displayed before my results. However, I'm trying to remove part of the file name when it is displayed.
The file names are formatted like this: aja_EPL_1999_03_01.txt
I want to have only the date without the beginning letters and without the .txt extension.
I've been searching for an answer and it seems like it's possible to do that with a sed or a grep command by using something like this to look forward and back and extract between _ and .txt:
(?<=_)\d+(?=\.)
But I must be doing something wrong, because it hasn't worked for me and I possibly have to add something as well, so that it doesn't extract only the first number, but the whole date. Thanks in advance.
Edit: Adding also the working command I've used just in case. I imagine whatever command is needed would have to go at the beginning?
sed '/^$/d' *.txt | grep -P '(^([A-ZÖÄÜÕŠŽ].*)?[Pp][Aa][Ll]{2}.*[^\.]$)' *.txt --colour -A 1
The results look like this:
aja_EPL_1999_03_02.txt:PALLILENNUD : korraga üritavad ümbermaailmalendu kaks meeskonda
A desired output would be this:
1999_03_02:PALLILENNUD : korraga üritavad ümbermaailmalendu kaks meeskonda
First off, you might want to think about your regular expression. While the one you have you say works, I wonder if it could be simplified. You told us:
(^([A-ZÖÄÜÕŠŽ].*)?[Pp][Aa][Ll]{2}.*[^\.]$)
It looks to me as if this is intended to match lines that start with a case insensitive "PALL", possibly preceded by any number of other characters that start with a capital letter, and that lines must not end in a backslash or a dot. So valid lines might be any of:
PALLILENNUD : korraga üritavad etc etc
Õlu on kena. Do I have appalling speling?
Peeter Pall is a limnologist at EMU!
If you'd care to narrow down this description a little and perhaps provide some examples of lines that should be matched or skipped, we may be able to do better. For instance, your outer parentheses are probably unnecessary.
Now, let's clarify what your pipe isn't doing.
sed '/^$/d' *.txt
This reads all your .txt files as an input stream, deletes any empty lines, and prints the output to stdout.
grep -P 'regex' *.txt --otheroptions
This reads all your .txt files, and prints any lines that match regex. It does not read stdin.
So .. in the command line you're using right now, your sed command is utterly ignored, as sed's output is not being read by grep. You COULD instruct grep to read from both files and stdin:
$ echo "hello" > x.txt
$ echo "world" | grep "o" x.txt -
x.txt:hello
(standard input):world
But that's not what you're doing.
By default, when grep reads from multiple files, it will precede each match with the name of the file from whence that match originated. That's also what you're seeing in my example above -- two inputs, one x.txt and the other - a.k.a. stdin, separated by a colon from the match they supplied.
While grep does include the most minuscule capability for filtering (with -o, or GNU grep's \K with optional Perl compatible RE), it does NOT provide you with any options for formatting the filename. Since you can'd do anything with the output of grep, you're limited to either parsing the output you've got, or using some other tool.
Parsing is easy, if your filenames are predictably structured as they seem to be from the two examples you've provided.
For this, we can ignore that these lines contain a file and data. For the purpose of the filter, they are a stream which follows a pattern. It looks like you want to strip off all characters from the beginning of each line up to and not including the first digit. You can do this by piping through sed:
sed 's/^[^0-9]*//'
Or you can achieve the same effect by using grep's minimal filtering to return every match starting from the first digit:
grep -o '[0-9].*'
If this kind of pipe-fitting is not to your liking, you may want to replace your entire grep with something in awk that combines functionality:
$ awk '
/[\.]$/ {next} # skip lines ending in backslash or dot
/^([A-ZÖÄÜÕŠŽ].*)?PALL/ { # lines to match
f=FILENAME
sub(/^[^0-9]*/,"",f) # strip unwanted part of filename, like sed
printf "%s:%s\n", f, $0
getline # simulate the "-A 1" from grep
printf "%s:%s\n", f, $0
}' *.txt
Note that I haven't tested this, because I don't have your data to work with.
Also, awk doesn't include any of the fancy terminal-dependent colourization that GNU grep provides through the --colour option.
I have two files, both contain tens of thousands of lines. I'm currently taking a string (Z1234562) from file_one.txt and trying to see if its on file_two.txt. If it's found on file_two.txt, I'm returning the line number the match was on -- in this case, line 1235. I have this working already.
file_one.txt
Line 1> [...]_Z1234562
file_two.txt
Line 1234> [...],Z1234561,[...]
Line 1235> [...],Z1234562,[...]
Line 1236> [...],Z1234563,[...]
However, I want to now append to line 1235 the string ,Yes. So that on file_two.txt I have
Line 1235> [...],Z1234562,[...],Yes
With the help Glenn Jackman's answer of this other question I was able to figure out how to add text using the ed editor before and after a specific line within a file. However, I haven't been able to figure out if with ed I can add text to the end of a line within a file. Reading the documentation I'm not sure there is. So far, based off this AIX site, this is what I have:
(echo '15022a'; echo 'Text to add.'; echo '.'; echo 'w'; echo 'q') | ed -s filename.txt
This appends the string Text to add. after line 15,022. I'm wondering if there is an insert equivalent to this append.
The reason I'm not using sed is because I'm on an AIX system and I can't seem to get what this forum has working. However, I'm not sure if the sed command in this forum only solves adding text before or after a line and not at the end of the line, which I already have working.
My next approach is to remove the return character at the end of the line I want to append to, append, and then re-add the return character but I don't want to reinvent the wheel before exhausting my options. Maybe I'm missing something as I want to do this as soon as possible but any help would be appreciated. I'm starting not to like these AIX systems. Maybe awk can help me but I'm less familiar with awk.
I wrote a small binary search subroutine using Perl in order to find the line that I want to append to. I'm not sure if sed, ed, grep, awk, etc. use binary search but that's why I'm not using ed or sed's pattern-replace searches. I want it to be as fast as possible so I'm open to a different approach.
Here is a general recipe I have used for invoking ed from a script:
(echo '/pattern/s/$/ new text/'
echo w ) | ed filename
This invokes ed on filename, searches for a line containing pattern, and appends "new text" at the end of that line. Season to taste.
You said you were having trouble with sed, but for the record, here's the same sort of thing using sed:
sed '/pattern/s/$/ new text/' filename > filename.modified
You can use the j command
(.,.+1)j
Joins the addressed lines. The addressed lines are deleted from the buffer and replaced by a single line containing their joined text. The current address is set to the resultant line.
So you just have to modifiy your previous command :
cat << EOF | ed -s filename.txt
15022a
Text to add.
.
-1,.j
wq
EOF
First we create a test file foo:
$ cat > foo
foo
bar
If you already know the line number you want to edit, e.g. previous example and line number 2 using sed:
$ sed '2s/$/foo' foo
foo
barfoo
In awk you'd command:
$ awk 'NR==2 {sub(/$/,"foo")} 1' foo
foo
barfoo
In perl:
$ perl -p -e 's/$/foo/ if $. == 2' foo
foo
barfoo
I need to calculate median value for the below input file. It is working fine for odd occurrences but not for even occurrences. Below is the input file and the script used. Could you please check what is wrong with this command and correct the same.
Input file:
col1,col2
AR,2.52
AR,3.57
AR,1.29
AR,6.66
AR,3.05
AR,5.52
Desired Output:
AR,3.31
Unix command:
cat test.txt | sort -t"," -k2n,2 | awk '{arr[NR]=$1} END { if (NR%2==1) print arr[(NR+1)/2]; else print (arr[NR/2]+arr[NR/2+1])/2}'
Don't forget that your input file has an additional line, containing the header. You need to take an additional step in your awk script to skip the first line.
Also, due to the fact you're using the default field separator, $1 will contain the whole line, so your code arr[NR/2]+arr[NR/2+1])/2 is never going to work. I would suggest that you changed it so that awk splits the input on a comma, then use the second field $2.
sort -t, -k2n,2 file | awk -F, 'NR>1{a[++i]=$2}END{if(i%2==1)print a[(i+1)/2];else print (a[i/2]+a[i/2+1])/2}'
I also removed your useless use of cat. Most tools, including sort and awk, are capable of reading in files directly, so you don't need to use cat with them.
Testing it out:
$ cat file
col1,col2
AR,2.52
AR,3.57
AR,1.29
AR,6.66
AR,3.05
AR,5.52
$ sort -t, -k2n,2 file | awk -F, 'NR>1{a[++i]=$2}END{if(i%2==1)print a[(i+1)/2];else print (a[i/2]+a[i/2+1])/2}'
3.31
It shouldn't be too difficult to modify the script slightly to change the output to whatever you want.
I want to use awk to get the second directory pattern I am able to do the same using cut -d command and need to use reverse as there is a problem that space between the two dir does not remains the same.
Here is the string I just want the third pattern one marked in bold. I am able to achieve this with cut -d and rev but want to achieve it with awk.
* example_view /nas/viewstore/admin/example_view.vws
please note the space between the two string varies so we cannot use a fixed value.
I used the following command to do so please take in to consideration of the * which comes when the view is set somewhere.
cleartool lsview -cview |rev | cut -d ' ' -f 1 | rev|xargs
Use awk as shown below:
cleartool lsview -cview | awk '{print $NF}'
$NF refers to the last field and, by default, awk uses whitespace as a delimiter.
As an alternative to dogbane's answer (upvoted), to get the view storage path (for dynamic view or snapshot view), I usually use string substitution when I am in a bash script:
cd /views/myStartedView
storagePath=$(cleartool lsview -cview)
storagePath="${storagePath#*/}/"
I think "cleartool pwv" (print working view) does the job.
For grep there's a fixed string option, -F (fgrep) to turn off regex interpretation of the search string.
Is there a similar facility for sed? I couldn't find anything in the man. A recommendation of another gnu/linux tool would also be fine.
I'm using sed for the find and replace functionality: sed -i "s/abc/def/g"
Do you have to use sed? If you're writing a bash script, you can do
#!/bin/bash
pattern='abc'
replace='def'
file=/path/to/file
tmpfile="${TMPDIR:-/tmp}/$( basename "$file" ).$$"
while read -r line
do
echo "${line//$pattern/$replace}"
done < "$file" > "$tmpfile" && mv "$tmpfile" "$file"
With an older Bourne shell (such as ksh88 or POSIX sh), you may not have that cool ${var/pattern/replace} structure, but you do have ${var#pattern} and ${var%pattern}, which can be used to split the string up and then reassemble it. If you need to do that, you're in for a lot more code - but it's really not too bad.
If you're not in a shell script already, you could pretty easily make the pattern, replace, and filename parameters and just call this. :)
PS: The ${TMPDIR:-/tmp} structure uses $TMPDIR if that's set in your environment, or uses /tmp if the variable isn't set. I like to stick the PID of the current process on the end of the filename in the hopes that it'll be slightly more unique. You should probably use mktemp or similar in the "real world", but this is ok for a quick example, and the mktemp binary isn't always available.
Option 1) Escape regexp characters. E.g. sed 's/\$0\.0/0/g' will replace all occurrences of $0.0 with 0.
Option 2) Use perl -p -e in conjunction with quotemeta. E.g. perl -p -e 's/\\./,/gi' will replace all occurrences of . with ,.
You can use option 2 in scripts like this:
SEARCH="C++"
REPLACE="C#"
cat $FILELIST | perl -p -e "s/\\Q$SEARCH\\E/$REPLACE/g" > $NEWLIST
If you're not opposed to Ruby or long lines, you could use this:
alias replace='ruby -e "File.write(ARGV[0], File.read(ARGV[0]).gsub(ARGV[1]) { ARGV[2] })"'
replace test3.txt abc def
This loads the whole file into memory, performs the replacements and saves it back to disk. Should probably not be used for massive files.
If you don't want to escape your string, you can reach your goal in 2 steps:
fgrep the line (getting the line number) you want to replace, and
afterwards use sed for replacing this line.
E.g.
#/bin/sh
PATTERN='foo*[)*abc' # we need it literal
LINENUMBER="$( fgrep -n "$PATTERN" "$FILE" | cut -d':' -f1 )"
NEWSTRING='my new string'
sed -i "${LINENUMBER}s/.*/$NEWSTRING/" "$FILE"
You can do this in two lines of bash code if you're OK with reading the whole file into memory. This is quite flexible -- the pattern and replacement can contain newlines to match across lines if needed. It also preserves any trailing newline or lack thereof, which a simple loop with read does not.
mapfile -d '' < file
printf '%s' "${MAPFILE//"$pat"/"$rep"}" > file
For completeness, if the file can contain null bytes (\0), we need to extend the above, and it becomes
mapfile -d '' < <(cat file; printf '\0')
last=${MAPFILE[-1]}; unset "MAPFILE[-1]"
printf '%s\0' "${MAPFILE[#]//"$pat"/"$rep"}" > file
printf '%s' "${last//"$pat"/"$rep"}" >> file
perl -i.orig -pse 'while (($i = index($_,$s)) >= 0) { substr($_,$i,length($s), $r)}'--\
-s='$_REQUEST['\'old\'']' -r='$_REQUEST['\'new\'']' sample.txt
-i.orig in-place modification with backup.
-p print lines from the input file by default
-s enable rudimentary parsing of command line arguments
-e run this script
index($_,$s) search for the $s string
substr($_,$i,length($s), $r) replace the string
while (($i = index($_,$s)) >= 0) repeat until
-- end of perl parameters
-s='$_REQUEST['\'old\'']', -r='$_REQUEST['\'new\'']' - set $s,$r
You still need to "escape" ' chars but the rest should be straight forward.
Note: this started as an answer to How to pass special character string to sed hence the $_REQUEST['old'] strings, however this question is a bit more appropriately formulated.
You should be using replace instead of sed.
From the man page:
The replace utility program changes strings in place in files or on the
standard input.
Invoke replace in one of the following ways:
shell> replace from to [from to] ... -- file_name [file_name] ...
shell> replace from to [from to] ... < file_name
from represents a string to look for and to represents its replacement.
There can be one or more pairs of strings.