unix : search a file if a string is present between two patterns - regex

I have a file, having a format, given below. I want to search if a word for e.g. 'hello' is present in line following schema and before the DocName. If it is present, how many such schema's have it?
How can I do this in one line using grep/awk/sed?
The expected output is: assuming I am searching if word 'hello' is present, then in this case it is present in 1st, 2nd and 4th schema, so the output is 3, since we have three 'hello' present in three schemas. Note even if there are multiple occurrences of 'hello' in first schema, it is still counted as one.
:
:
:
DocName: abjrkj.txt
schema:
abs
askj
djsk
djsk
hello
adj
hello
DocName: abjrkj.txt
schema:
abs
askj
djsk
djsk
adj
hello
DocName: aasjrkj.txt
schema:
absasd
askjas
djsksa
djskasd
adjsg
DocName: ghhd.txt
schema:
absg
fdgaskj
dgdjsk
dgdfdjsk
drgadj
hello
:
:
:

Try this.
awk -F '^DocName:' '/hello/ { ++i }
END { print i }' file
If you absolutely require a one-line solution (why??) the whitespace can be condensed to just one space.

Here is sed solution:
sed ':a; N; s/\n/ /; $!ba; s/DocName/\n&/g' < file | sed -n '/DocName/{/hello/p}' | wc
This is algorithm: It puts whole file in pattern space with replacing all \n characters with space. Then before every DocName string puts \n. After that is piping throw searching Docname & hello finally prints 3 numbers from which first is asked. If you want to see printed lines omit | wc piping for test reasons. Maybe more elegant sed solution exists playing with pattern & hold space!

Since your input file has schemas separated by blank lines you can use awk in paragraph mode and then it's simply:
$ awk -v RS= '/hello/{++c} END{print c}' file
3

Related

Regex: find elements regardless of order

If I have the string:
geo:FR, host:www.example.com
(In reality the string is more complicated and has more fields.)
And I want to extract the "geo" value and the "host" value, I am facing a problem when the order of the keys change, as in the following:
host:www.example.com, geo:FR
I tried this line:
sed 's/.\*geo:\([^ ]*\).\*host:\([^ ]*\).*/\1,\2/'
But it only works on the first string.
Is there a way to do it in a single regex, and if not, what's the best approach?
I suggest extracting each text you need with a separate sed command:
s="geo:FR, host:www.example.com"
host="$(sed -n 's/.*host:\([^[:space:],]*\).*/\1/p' <<< "$s")"
geo="$(sed -n 's/.*geo:\([^[:space:],]*\).*/\1/p' <<< "$s")"
See the online demo, echo "$host and $geo" prints
www.example.com and FR
for both inputs.
Details
-n suppresses line output and p prints the matches
.* - matches any 0+ chars up the last...
host: - host: substring and then
\([^[:space:],]*\) - captures into Group 1 any 0 or more chars other than whitespace and a comma
.* - the rest of the line.
The result is just the contents of Group 1 (see \1 in the replacement pattern).
Whenever you have tag/name to value pairs in your input I find it best (clearest, simplest, most robust,, easiest to enhance, etc.) to first create an array that contains that mapping (f[] below) and then you can simply access the values by their tags:
$ cat file
geo:FR, host:www.example.com
host:www.example.com, geo:FR
foo:bar, host:www.example.com, stuff:nonsense, badgeo:uhoh, geo:FR, nastygeo:wahwahwah
$ cat tst.awk
BEGIN { FS=":|, *"; OFS="," }
{
for (i=1; i<=NF; i+=2) {
f[$i] = $(i+1)
}
print f["geo"], f["host"]
}
$ awk -f tst.awk file
FR,www.example.com
FR,www.example.com
FR,www.example.com
The above will work using any awk in any shell on every UNIX box.
Here I've used GNU Awk to convert your delimited key:value pairs to valid shell assignment. With Bash, you can load these assignments into your current shell using <(process substitution):
# source the file descriptor generated by proc sub
. < <(
# use comma-space as field separator, literal apostrophe as variable q
awk -F', ' -vq=\' '
# change every foo:bar in line to foo='bar' on its own line
{for(f=1;f<=NF;f++) print gensub(/:(.*)/, "=" q "\\1" q, 1, $f)}
# use here-string to load text; remove everything but first quote to use standard input
' <<< 'host:www.example.com, geo:FR'
)

How can I merge multiple blocks/lines with sed or regex?

Is it possible to merge multiple blocks/lines into a "single" line?
So basically if the next line starts with the same "#Msg" tag then append it to the previous line. (Hard to explain, but my example speaks for itself) (The blocks are separated by a new/blank line)
My input file looks like this:
#Msg,00000
#Msg,00001
#Msg,00002
#Msg,00003
#Msg,00004
#Msg,00005
#Msg,00006
#Msg,00007
#Msg,00008
#Msg,00009
#Msg,00010
#Msg,00011
Output should be like this:
#Msg,00000
#Msg,00001 #Msg,00002
#Msg,00003 #Msg,00004
#Msg,00005
#Msg,00006 #Msg,00007 #Msg,00008
#Msg,00009
#Msg,00010 #Msg,00011
Any advice is very welcome.
This would be pretty easy to do in Perl:
perl -00 -ple 'tr/\n/ /'
-e CODE specifies the program.
-p wraps a read/write line loop around it (by default it reads from STDIN, but you can also specify one or more filenames on the command line).
-00 specifies that the input "lines" are actually paragraphs.
-l has two effects: Incoming line terminators are automatically stripped from lines, and outgoing lines get line terminators added to them (and because we used -00 (paragraph mode), our line terminator is actually \n\n).
To recap:
We read the input one paragraph at a time. For each paragraph, we remove any trailing newlines. We then translate every newline to a space. Finally we output the transformed paragraph, followed by \n\n.
No point in trying to produce a shorter code than is possible with Perl!
Collect lines from the input file in list group until a blank line appears. Then output the contents of group, empty it and start again. When end-of-file is encountered output whatever is in group, if it is non-empty.
group = []
with open('vollschauer.txt') as vollschauer:
for line in vollschauer:
line = line.rstrip()
if line:
group.append(line)
else:
if group:
print (' '.join(group))
print()
group = []
if group:
print (' '.join(group))
group = []
$ awk -v RS= -v ORS='\n\n' '{$1=$1}1' file
#Msg,00000
#Msg,00001 #Msg,00002
#Msg,00003 #Msg,00004
#Msg,00005
#Msg,00006 #Msg,00007 #Msg,00008
#Msg,00009
#Msg,00010 #Msg,00011
If you insist on using sed, this should do the trick:
sed -r ':a; N; /^(#[^,]+,).*\n\1/! { P; D }; s/\n/ /; ba' file
It takes different tags into account. Such tags won't be grouped together (that's what I understood is the desired behavior):
$ cat file
#Msg,00000
#Msg,00001
#Hello,00002
#Hello,00003
#What,00004
#What,00005
$ sed -r ':a; N; /^(#[^,]+,).*\n\1/! { P; D }; s/\n/ /; ba' file
#Msg,00000 #Msg,00001
#Hello,00002
#Hello,00003
#What,00004 #What,00005
Note that this solution uses GNU sed.
This might work for you (GNU sed):
sed ':a;N;/^$/M!s/\n/ /;ta' file
Gather up lines, replacing each newline by a space until an empty line.
N.B. The use of the M flag on the repexp /^$/ which matches an empty line on a pattern space containing multiple lines.

get the last word in body of text

Given a body of text than can span a varying number of lines, I need to use a grep, sed or awk solution to search through many files for the same pattern and get the last word in the body.
A file can include formats such as these where the word I want can be named anything
call function1(input1,
input2, #comment
input3) #comment
returning randomname1,
randomname2,
success3
call function1(input1,
input2,
input3)
returning randomname3,
randomname2,
randomname3
call function1(input1,
input2,
input3)
returning anothername3,
randomname2, anothername3
I need to print out results as
success3
randomname3
anothername3
Also I need some the filename and line information about each .
I've tried
pcregrep -M 'function1.*(\s*.*){6}(\w+)$' filename.txt
which is too greedy and I still need to print out just the specific grouped value and not the whole pattern. The words function1 and returning in my sample code will always be named as this and can be hard coded within my expression.
Last word of code blocks
Split file in blocks using awk's record separator RS. A record will be defined as a block of text, records are separated by double newlines.
A record consists of fields, each two consecutive fields are separated by white space or a single newline.
Now all we have to do is print the last field for each record, resulting in following code:
awk 'BEGIN{ FS="[\n\t ]"; RS="\n\n"} { print $NF }' file
Explanation:
FS this is the field separator and is set to either a newline, a tab or a space: [\n\t ].
RS this is the record separator and is set to a doulbe newline: \n\n
print $NF this will print the field $ with index NF, which is a variable containing the number of fields. Hence this prints the last field.
Note: To capture all paragraphs the file should end in double newline, this can easily be achieved by pre processing the file using: $ echo -e '\n\n' >> file.
Alternate solution based on comments
A more elegant ans simple solution is as follows:
awk -v RS='' '{ print $NF }' file
How about the following awk solution:
awk 'NF == 0 {if(last) print last; last=""} NF > 0 {last=$NF} END {print last}' file
the $NF is getting the value of the last "word" where NF stands for number of fields. Then the last variable always stores the last word on a line and prints it if it encounters an empty line, representing the end of a paragraph.
New version with matches function1 condition.
awk 'NF == 0 {if(last && hasF) print last; last=hasF=""}
NF > 0 {last=$NF; if(/function1/)hasF=1}
END {if(hasF) print last}' filename.txt
This will produce the output you show from the input file you posted:
$ awk -v RS= '{print $NF}' file
success3
randomname3
anothername3
If you want to print FILENAME and line number like you mention then this may be what you want:
$ cat tst.awk
NF { nr=NR; last=$NF; next }
{ prt() }
END { prt() }
function prt() { if (nr) print FILENAME, nr, last; nr=0 }
$ awk -f tst.awk file
file 6 success3
file 13 randomname3
file 20 anothername3
If that doesn't do what you want, edit your question to provide clearer, more truly representative and accurate sample input and expected output.
This is the perl version of Shellfish's awk solution (plus the keywords):
perl -00 -nE '/function1/ and /returning/ and say ((split)[-1])' file
or, with one regex:
perl -00 -nE '/^(?=.*function1)(?=.*returning).*?(\S+)\s*$/s and say $1' file
But the key is the -00 option which reads the file a paragraph at a time.

Remove \n newline if string contains keyword

I'd like to know if I can remove a \n (newline) only if the current line has one ore more keywords from a list; for instance, I want to remove the \n if it contains the words hello or world.
Example:
this is an original
file with lines
containing words like hello
and world
this is the end of the file
And the result would be:
this is an original
file with lines
containing words like hello and world this is the end of the file
I'd like to use sed, or awk and, if needed, grep, wc or whatever commands work for this purpose. I want to be able to do this on a lot of files.
Using awk you can do:
awk '/hello|world/{printf "%s ", $0; next} 1' file
this is an original
file with lines
containing words like hello and world this is the end of the file
here is simple one using sed
sed -r ':a;$!{N;ba};s/((hello|world)[^\n]*)\n/\1 /g' file
Explanation
:a;$!{N;ba} read whole file into pattern, like this: this is an original\nfile with lines\ncontaining words like hell\
o\nand world\nthis is the end of the file$
s/((hello|world)[^\n]*)\n/\1 /g search the key words hello or world and remove the next \n,
g command in sed substitute stands to apply the replacement to all matches to the regexp, not just the first.
A non-regex approach:
awk '
BEGIN {
# define the word list
w["hello"]
w["world"]
}
{
printf "%s", $0
for (i=1; i<=NF; i++)
if ($i in w) {
printf " "
next
}
print ""
}
'
or a perl one-liner
perl -pe 'BEGIN {#w = qw(hello world)} s/\n/ / if grep {$_ ~~ #w} split'
To edit the file in-place, do:
awk '...' filename > tmpfile && mv tmpfile filename
perl -i -pe '...' filename
This might work for you (GNU sed):
sed -r ':a;/^.*(hello|world).*\'\''/M{$bb;N;ba};:b;s/\n/ /g' file
This checks if the last line, of a possible multi-line, contains the required string(s) and if so reads another line until end-of-file or such that the last line does not contain the/those string(s). Newlines are removed and the line printed.
$ awk '{ORS=(/hello|world/?FS:RS)}1' file
this is an original
file with lines
containing words like hello and world this is the end of the file
sed -n '
:beg
/hello/ b keep
/world/ b keep
H;s/.*//;x;s/\n/ /g;p;b
: keep
H;s/.*//
$ b beg
' YourFile
a bit harder due to check on current line that may include a previous hello or world already
principle:
on every pattern match, keep the string in hold buffer
other wise, load hold buffer and remove \n (use of swap and empty the current line due to limited buffer operation available) and print the content
Add a special case of pattern in last line (normaly hold so not printed otherwise)

SED: addressing two lines before match

Print line, which is situated 2 lines before the match(pattern).
I tried next:
sed -n ': loop
/.*/h
:x
{n;n;/cen/p;}
s/./c/p
t x
s/n/c/p
t loop
{g;p;}
' datafile
The script:
sed -n "1N;2N;/XXX[^\n]*$/P;N;D"
works as follows:
Read the first three lines into the pattern space, 1N;2N
Search for the test string XXX anywhere in the last line, and if found print the first line of the pattern space, P
Append the next line input to pattern space, N
Delete first line from pattern space and restart cycle without any new read, D, noting that 1N;2N is no longer applicable
This might work for you (GNU sed):
sed -n ':a;$!{N;s/\n/&/2;Ta};/^PATTERN\'\''/MP;$!D' file
This will print the line 2 lines before the PATTERN throughout the file.
This one with grep, a bit simpler solution and easy to read [However need to use one pipe]:
grep -B2 'pattern' file_name | sed -n '1,2p'
If you can use awk try this:
awk '/pattern/ {print b} {b=a;a=$0}' file
This will print two line before pattern
I've tested your sed command but the result is strange (and obviously wrong), and you didn't give any explanation. You will have to save three lines in a buffer (named hold space), do a pattern search with the newest line and print the oldest one if it matches:
sed -n '
## At the beginning read three lines.
1 { N; N }
## Append them to "hold space". In following iterations it will append
## only one line.
H
## Get content of "hold space" to "pattern space" and check if the
## pattern matches. If so, extract content of first line (until a
## newline) and exit.
g
/^.*\nsix$/ {
s/^\n//
P
q
}
## Remove the old of the three lines saved and append the new one.
s/^\n[^\n]*//
h
' infile
Assuming and input file (infile) with following content:
one
two
three
four
five
six
seven
eight
nine
ten
It will search six and as output will yield:
four
Here are some other variants:
awk '{a[NR]=$0} /pattern/ {f=NR} END {print a[f-2]}' file
This stores all lines in an array a. When pattern is found store line number.
At then end print that line number from the file.
PS may be slow with large files
Here is another one:
awk 'FNR==NR && /pattern/ {f=NR;next} f-2==FNR' file{,}
This reads the file twice (file{,} is the same as file file)
At first round it finds the pattern and store line number in variable f
Then at second round it prints the line two before the value in f