Count occurrences of character per line/field on Unix

Question

Given a file with data like this (ie stores.dat file)

sid|storeNo|latitude|longitude 2tt|1|-28.0372000t0|153.42921670 9|2t|-33tt.85t09t0000|15t1.03274200 

What is the command that would return the number of occurrences of the 't' character per line?

eg. would return:

count   lineNum    4       1    3       2    6       3 

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Also, to do it by count of occurrences by field what is the command to return the following results?

eg. input of column 2 and character 't'

count   lineNum    1       1    0       2    1       3 

eg. input of column 3 and character 't'

count   lineNum    2       1    1       2    4       3 

Answer 1

To count occurrence of a character per line you can do:

awk -F'|' 'BEGIN{print "count", "lineNum"}{print gsub(/t/,"") "\t" NR}' file count lineNum 4       1 3       2 6       3 

To count occurrence of a character per field/column you can do:

column 2:

awk -F'|' -v fld=2 'BEGIN{print "count", "lineNum"}{print gsub(/t/,"",$fld) "\t" NR}' file count lineNum 1       1 0       2 1       3 

column 3:

awk -F'|' -v fld=3 'BEGIN{print "count", "lineNum"}{print gsub(/t/,"",$fld) "\t" NR}' file count lineNum 2       1 1       2 4       3 

• gsub() function's return value is number of substitution made. So we use that to print the number.
• NR holds the line number so we use it to print the line number.
• For printing occurrences of particular field, we create a variable fld and put the field number we wish to extract counts from.

Answer 2

grep -n -o "t" stores.dat | sort -n | uniq -c | cut -d : -f 1 

gives almost exactly the output you want:

  4 1   3 2   6 3 

Thanks to @raghav-bhushan for the grep -o hint, what a useful flag. The -n flag includes the line number as well.