How do I count the number of rows and columns in a file using bash?

Question

Say I have a large file with many rows and many columns. I\'d like to find out how many rows and columns I have using bash.

Answer 1

Columns: awk '{print NF}' file | sort -nu | tail -n 1

Use head -n 1 for lowest column count, tail -n 1 for highest column count.

Rows: cat file | wc -l or wc -l < file for the UUOC crowd.

Answer 2

Alternatively to count columns, count the separators between columns. I find this to be a good balance of brevity and ease to remember. Of course, this won't work if your data include the column separator.

head -n1 myfile.txt | grep -o " " | wc -l

Uses head -n1 to grab the first line of the file. Uses grep -o to to count all the spaces, and output each space found on a new line. Uses wc -l to count the number of lines.

Answer 3

Simple row count is $(wc -l "$file"). Use $(wc -lL "$file") to show both the number of lines and the number of characters in the longest line.

Answer 4

For rows you can simply use wc -l file

-l stands for total line

for columns uou can simply use head -1 file | tr ";" "\n" | wc -l

Explanation
head -1 file
Grabbing the first line of your file, which should be the headers, and sending to it to the next cmd through the pipe
| tr ";" "\n"

tr stands for translate.
It will translate all ; characters into a newline character.
In this example ; is your delimiter.

Then it sends data to next command.

wc -l
Counts the total number of lines.

Answer 5

Following code will do the job and will allow you to specify field delimiter. This is especially useful for files containing more than 20k lines.

awk 'BEGIN { 
  FS="|"; 
  min=10000; 
}
{ 
  if( NF > max ) max = NF; 
  if( NF < min ) min = NF;
} 
END { 
  print "Max=" max; 
  print "Min=" min; 
} ' myPipeDelimitedFile.dat

Answer 6

A very simple way to count the columns of the first line in pure bash (no awk, perl, or other languages):

read -r line < $input_file
ncols=`echo $line | wc -w`

This will work if your data are formatted appropriately.