Using awk to count the number of occurrences of a word in a column
Use an array awk ‘{count[$3]++} END {for (word in count) print word, count[word]}’ file If you want “block” specifically: END {print count[“BLOCK”]}
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Sort an associative array in awk
Instead of asort, use asorti(source, destination) which sorts the indices into a new array and you won’t have to copy the array. Then you can use the destination array as pointers into the source array. For your example, you would use it like this: n=asorti(chr_count, sorted) for (i=1; i<=n; i++) { print sorted[i] ” : … Read more
Print all Fields with AWK separated by OFS
This is a variation on the first style: echo “1 2 3 4″ | gawk ‘BEGIN { OFS=” 🙁 “}; {$1=$1; print $0}’ Results: 1 🙁 2 🙁 3 🙁 4 Explanation: the $1=$1 is to rebuild the record, using the current OFS (you can also see http://www.gnu.org/software/gawk/manual/gawk.html#Changing-Fields) Update: (suggested by @EdMorton and @steve) This … Read more
awk: find minimum and maximum in column
Awk guesses the type. String “10” is less than string “4” because character “1” comes before “4”. Force a type conversion, using addition of zero: min=`awk ‘BEGIN{a=1000}{if ($1<0+a) a=$1} END{print a}’ mydata.dat` max=`awk ‘BEGIN{a= 0}{if ($1>0+a) a=$1} END{print a}’ mydata.dat`
How to insert a line using sed before a pattern and after a line number?
You can either write a sed script file and use: sed -f sed.script file1 … Or you can use (multiple) -e ‘command’ options: sed -e ‘/SysAdmin/i\ Linux Scripting’ -e ‘1,$s/A/a/’ file1 … If you want to append something after a line, then: sed -e ‘234a\ Text to insert after line 234’ file1 …
String comparison in awk
Sure it can: pax$ echo ‘hello goodbye’ | gawk ‘{if ($0 == “hello”) {print “HELLO”}}’ HELLO You can also do inequality (ordered) testing as well: pax> printf ‘aaa\naab\naac\naad\n’ | gawk ‘{if ($1 < “aac”){print}}’ aaa aab
Awk if else issues
You forgot braces around the if block, and a semicolon between the statements in the block. awk ‘{if($3 != 0) {a = ($3/$4); print $0, a;} else if($3==0) print $0, “-” }’ file > out
matching a line with a literal asterisk “*” in grep
Try a character class instead echo “$STRING” | egrep ‘[*]’
ignorecase in AWK
Add IGNORECASE = 1; to the beginning of your awk command like so: bash-3.2$ echo “Create” | awk ‘/^create/;’ bash-3.2$ echo “Create” | awk ‘IGNORECASE = 1;/^create/;’ Create
Check if all of multiple strings or regexes exist in a file
Awk is the tool that the guys who invented grep, shell, etc. invented to do general text manipulation jobs like this so not sure why you’d want to try to avoid it. In case brevity is what you’re looking for, here’s the GNU awk one-liner to do just what you asked for: awk ‘NR==FNR{a[$0];next} {for(s … Read more