Greping asterisk through bash - bash

I am validating few columns in a pipe delimited file. My second column is defaulted with '*'.
E.g. data of file to be validated:
abc|* |123
def|** |456
ghi|* |789
2nd record has 2 stars due to erroneous data.
I teied it as:
Value_to_match="*"
unmatch_count=cat <filename>| cut -d'|' -f2 | awk '{$1=$1};1' | grep -vw "$Value_to_match" | sort -n | uniq | wc -l
echo "unmatch_count"
This gives me count as 0 whereas I am expecting 1 (for **) as I have used -w with grep which is exact match and -v which is invert match.
How can I grep **?

The problem here is grep considering ** a regular expression. To prevent this, use -F to use fixed strings:
grep -F '**' file
However, you have an unnecessarily big set of piped operations, while awk alone can handle it quite well.
If you want to check lines containing ** in the second column, say:
$ awk -F"|" '$2 ~ /\*\*/' file
def|** |456
If you want to count how many of such lines you have, say:
$ awk -F"|" '$2 ~ /\*\*/ {sum++} END {print sum}' file
1
Note the usage of awk:
-F"|" to set the field separator to |.
$2 ~ /\*\*/ to say: hey, in every line check if the second field contains two asterisks (remember we sliced lines by |). We are escaping the * because it has a special meaning as a regular expression.
If you want to output those lines that have just one asterisk as second field, say:
$ awk -F"|" '$2 ~ /^*\s*$/' file
abc|* |123
ghi|* |789
Or check for those not matching this regex with !~:
$ awk -F"|" '$2 !~ /^*\s*$/' a
def|** |456

Related

Count number of Special Character in Unix Shell

I have a delimited file that is separated by octal \036 or Hexadecimal value 1e.
I need to count the number of delimiters on each line using a bash shell script.
I was trying to use awk, not sure if this is the best way.
Sample Input (| is a representation of \036)
Example|Running|123|
Expected output:
3
awk -F'|' '{print NF-1}' file
Change | to whatever separator you like. If your file can have empty lines then you need to tweak it to:
awk -F'|' '{print (NF ? NF-1 : 0)}' file
You can try
awk '{print gsub(/\|/,"")}'
Simply try
awk -F"|" '{print substr($3,length($3))}' OFS="|" Input_file
Explanation: Making field separator -F as | and then printing the 3rd column by doing $3 only as per your need. Then setting OFS(output field separator) to |. Finally mentioning Input_file name here.
This will work as far as I know
echo "Example|Running|123|" | tr -cd '|' | wc -c
Output
3
This should work for you:
awk -F '\036' '{print NF-1}' file
3
-F '\036' sets input field delimiter as octal value 036
Awk may not be the best tool for this. Gnu grep has a cool -o option that prints each matching pattern on a separate line. You can then count how many matching lines are generated for each input line, and that's the count of your delimiters. E.g. (where ^^ in the file is actually hex 1e)
$ cat -v i
a^^b^^c
d^^e^^f^^g
$ grep -n -o $'\x1e' i | uniq -c
2 1:
3 2:
if you remove the uniq -c you can see how it's working. You'll get "1" printed twice because there are two matching patterns on the first line. Or try it with some regular ascii characters and it becomes clearer what the -o and -n options are doing.
If you want to print the line number followed by the field count for that line, I'd do something like:
$grep -n -o $'\x1e' i | tr -d ':' | uniq -c | awk '{print $2 " " $1}'
1 2
2 3
This assumes that every line in the file contains at least one delimiter. If that's not the case, here's another approach that's probably faster too:
$ tr -d -c $'\x1e\n' < i | awk '{print length}'
2
3
0
0
0
This uses tr to delete (-d) all characters that are not (-c) 1e or \n. It then pipes that stream of data to awk which just counts how many characters are left on each line. If you want the line number, add " | cat -n" to the end.

match awk column value to a column in another file

I need to know if I can match awk value while I am inside a piped command. Like below:
somebinaryGivingOutputToSTDOUT | grep -A3 "sometext" | grep "somemoretext" | awk -F '[:|]' 'BEGIN{OFS=","; print "Col1,Col2,Col3,Col4"}{print $4,$6,$4*10^10+$6,$8}'
from here I need to check if the computed value $4*10^10+$6 is present (matches to) in any of the column value of another file. If it is present then print, else just move forward.
File where value needs to be matched is as below:
a,b,c,d,e
1,2,30000000000,3,4
I need to match with the 3rd column of the above file.
I would ideally like this to be in the same command, because if this check is not applied, it prints more than 100 million rows (and a large file).
I have already read this question.
Adding more info:
Breaking my command into parts
part1-command:
somebinaryGivingOutputToSTDOUT | grep -A3 "sometext" | grep "Something:"
part1-output(just showing 1 iteration output):
Something:38|Something1:1|Something2:10588429|Something3:1491539456372358463
part2-command Now I use awk
awk -F '[:|]' 'BEGIN{OFS=","; print "Col1,Col2,Col3,Col4"}{print $4,$6,$4*10^10+$6,$8}'
part2-command output: currently below values are printed (see how i multiplied 1*10^10+10588429 and got 10010588429
1,10588429,10010588429,1491539456372358463
3,12394810,30012394810,1491539456372359082
1,10588430,10010588430,1491539456372366413
Now here I need to put a check (within the command [near awk]) to print only if 10010588429 was present in another file (say another_file.csv as below)
another_file.csv
A,B,C,D,E
1,2, 10010588429,4,5
x,y,z,z,k
10,20, 10010588430,40,50
output should only be
1,10588429,10010588429,1491539456372358463
1,10588430,10010588430,1491539456372366413
So for every row of awk we check entry in file2 column C
Using the associative array approach in previous question, include a hyphen in place of the first file to direct AWK to the input stream.
Example:
grep -A3 "sometext" | grep "somemoretext" | awk -F '[:|]'
'BEGIN{OFS=","; print "Col1,Col2,Col3,Col4"}
NR==FNR {
query[$4*10^10+$6]=$4*10^10+$6;
out[$4*10^10+$6]=$4 FS $6 FS $4*10^10+$6 FS $8;
next
}
query[$3]==$3 {
print out[$3]
}' - another_file.csv > output.csv
More info on the merging process in the answer cited in the question:
Using AWK to Process Input from Multiple Files
I'll post a template which you can utilize for your computation
awk 'BEGIN {FS=OFS=","}
NR==FNR {lookup[$3]; next}
/sometext/ {c=4}
c&&c--&&/somemoretext/ {value= # implement your computation here
if(value in lookup)
print "what you want"}' lookup.file FS=':' grep.files...
here awk loads up the values in the third column of the first file (which is comma delimited) into the lookup array (a hashmap in disguise). For the next set of files, sets the delimiter to : and similar to grep -A3 looks within the 3 distance of the first pattern for the second pattern, does the computation and prints what you want.
In awk you can have more control on what column your pattern matches as well, here I replicated grep example.
This is another simplified example to focus on the core of the problem.
awk 'BEGIN{for(i=1;i<=1000;i++) print int(rand()*1000), rand()}' |
awk 'NR==FNR{lookup[$1]; next}
$1 in lookup' perfect.numbers -
first process creates 1000 random records, and second one filters the ones where the first fields is in the look up table.
28 0.736027
496 0.968379
496 0.404218
496 0.151907
28 0.0421234
28 0.731929
for the lookup file
$ head perfect.numbers
6
28
496
8128
the piped data is substituted as the second file at -.
You can pipe your grep or awk output into a while read loop which gives you some degree of freedom. There you could decide on whether to forward a line:
grep -A3 "sometext" | grep "somemoretext" | while read LINE; do
COMPUTED=$(echo $LINE | awk -F '[:|]' 'BEGIN{OFS=","}{print $4,$6,$4*10^10+$6,$8}')
if grep $COMPUTED /the/file/to/search &>/dev/null; then
echo $LINE
fi
done | cat -

How to truncate trailing space in xargs

I would like to use xargs to list the contents of some files based on the output of command A. Xargs replace-str seem to be adding a space to the end and causing the command to fail. Any suggestions? I know this can be worked around using for loop. But curious to know how to do this using xargs.
lsscsi |awk -F\/ '/ATA/ {print $NF}' | xargs -L 1 -I % cat /sys/block/%/queue/scheduler
cat: /sys/block/sda /queue/scheduler: No such file or directory
The problem is not with xargs -I, which does not append a space to each argument, which can be verified as follows:
$ echo 'sda' | xargs -I % echo '[%]'
[sda]
Incidentally, specifying -L 1 in addition to -I is pointless: -I implies line-by-line processing.
Therefore, it must be the output from the command that provides input to xargs that contains the trailing space.
You can adapt your awk command to fix that:
lsscsi |
awk -F/ '/ATA/ {sub(/ $/,"", $NF); print $NF}' |
xargs -I % cat '/sys/block/%/queue/scheduler'
sub(/ $/,"", $NF) replaces a trailing space in field $NF with the empty string, thereby effectively removing it.
Note how I've (single-)quoted cat's argument so as to make it work even with filenames with spaces.
lsscsi |awk -F\/ '/ATA/ {print $NF}'| awk '{print $NF}' | xargs -L 1 -I % cat /sys/block/%/queue/scheduler
The first awk stmt splits by "/" so anything else is considered as field. In this is case "sda " becomes whole field including a space at the end. But by default, awk removes space . So after the pipe, the second awk prints $NF (which is last word of the line) and leaves out " " space as delimiter. awk { print $1 } will do the same because we have only one word, "sda" which is both first and last.

grep - how to display another word instead of the matching of grep

Given input like:
ID VALUE
technique lol
technology case
london knife
ocean sky
I'm currently using
grep -Eo '^[^ ]+' FILE | grep "tech"
for match every word which contain "tech" in the ID column.
In this case, it display :
technique
technology
However does anyone can tell me how can I display the word from the second column regarding the word matching in the first column ?
For example how to display the word:
lol
case
(display the value instead the key)
Also, how can I display the key (as above) and the value separate by "=" like ? (without any spaces):
key=value
Thanks
You can grep for lines starting with "tech" and then just display the second column. The exact format depends on how your input file columns are separated. If they are tab separated:
grep '^tech' FILE | cut -f 2
If they are space separated:
grep '^tech' FILE | tr -s ' ' $'\t' | cut -f 2
This "squeezes" repeated spaces and replaces them with a single tab character.
For your second question, you can use
sed -n '/^tech/ s/[[:space:]]\+/=/p' FILE
This means "don't print (-n); on lines matching ^tech, make the substitution and print".
Using awk:
awk '$1 ~ "tech" {print $2}' < inputfile
or with key=value
awk '$1 ~ "tech" {print $1"="$2}' < inputfile

awk - split only by first occurrence

I have a line like:
one:two:three:four:five:six seven:eight
and I want to use awk to get $1 to be one and $2 to be two:three:four:five:six seven:eight
I know I can get it by doing sed before. That is to change the first occurrence of : with sed then awk it using the new delimiter.
However replacing the delimiter with a new one would not help me since I can not guarantee that the new delimiter will not already be somewhere in the text.
I want to know if there is an option to get awk to behave this way
So something like:
awk -F: '{print $1,$2}'
will print:
one two:three:four:five:six seven:eight
I will also want to do some manipulations on $1 and $2 so I don't want just to substitute the first occurrence of :.
Without any substitutions
echo "one:two:three:four:five" | awk -F: '{ st = index($0,":");print $1 " " substr($0,st+1)}'
The index command finds the first occurance of the ":" in the whole string, so in this case the variable st would be set to 4. I then use substr function to grab all the rest of the string from starting from position st+1, if no end number supplied it'll go to the end of the string. The output being
one two:three:four:five
If you want to do further processing you could always set the string to a variable for further processing.
rem = substr($0,st+1)
Note this was tested on Solaris AWK but I can't see any reason why this shouldn't work on other flavours.
Some like this?
echo "one:two:three:four:five:six" | awk '{sub(/:/," ")}1'
one two:three:four:five:six
This replaces the first : to space.
You can then later get it into $1, $2
echo "one:two:three:four:five:six" | awk '{sub(/:/," ")}1' | awk '{print $1,$2}'
one two:three:four:five:six
Or in same awk, so even with substitution, you get $1 and $2 the way you like
echo "one:two:three:four:five:six" | awk '{sub(/:/," ");$1=$1;print $1,$2}'
one two:three:four:five:six
EDIT:
Using a different separator you can get first one as filed $1 and rest in $2 like this:
echo "one:two:three:four:five:six seven:eight" | awk -F\| '{sub(/:/,"|");$1=$1;print "$1="$1 "\n$2="$2}'
$1=one
$2=two:three:four:five:six seven:eight
Unique separator
echo "one:two:three:four:five:six seven:eight" | awk -F"#;#." '{sub(/:/,"#;#.");$1=$1;print "$1="$1 "\n$2="$2}'
$1=one
$2=two:three:four:five:six seven:eight
The closest you can get with is with GNU awk's FPAT:
$ awk '{print $1}' FPAT='(^[^:]+)|(:.*)' file
one
$ awk '{print $2}' FPAT='(^[^:]+)|(:.*)' file
:two:three:four:five:six seven:eight
But $2 will include the leading delimiter but you could use substr to fix that:
$ awk '{print substr($2,2)}' FPAT='(^[^:]+)|(:.*)' file
two:three:four:five:six seven:eight
So putting it all together:
$ awk '{print $1, substr($2,2)}' FPAT='(^[^:]+)|(:.*)' file
one two:three:four:five:six seven:eight
Storing the results of the substr back in $2 will allow further processing on $2 without the leading delimiter:
$ awk '{$2=substr($2,2); print $1,$2}' FPAT='(^[^:]+)|(:.*)' file
one two:three:four:five:six seven:eight
A solution that should work with mawk 1.3.3:
awk '{n=index($0,":");s=$0;$1=substr(s,1,n-1);$2=substr(s,n+1);print $1}' FS='\0'
one
awk '{n=index($0,":");s=$0;$1=substr(s,1,n-1);$2=substr(s,n+1);print $2}' FS='\0'
two:three:four five:six:seven
awk '{n=index($0,":");s=$0;$1=substr(s,1,n-1);$2=substr(s,n+1);print $1,$2}' FS='\0'
one two:three:four five:six:seven
Just throwing this on here as a solution I came up with where I wanted to split the first two columns on : but keep the rest of the line intact.
Comments inline.
echo "a:b:c:d::e" | \
awk '{
split($0,f,":"); # split $0 into array of fields `f`
sub(/^([^:]+:){2}/,"",$0); # remove first two "fields" from `$0`
print f[1],f[2],$0 # print first two elements of `f` and edited `$0`
}'
Returns:
a b c:d::e
In my input I didn't have to worry about the first two fields containing escaped :, if that was a requirement, this solution wouldn't work as expected.
Amended to match the original requirements:
echo "a:b:c:d::e" | \
awk '{
split($0,f,":");
sub(/^([^:]+:)/,"",$0);
print f[1],$0
}'
Returns:
a b:c:d::e

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