unix - count of columns in file

Question

Given a file with data like this  i e  stores dat file   sid storeNo latitude longitude 2 1 -28 03720000 153 42921670 9 2 -33 85090000 151 03274200   What would be a command to output the number of column names   i e  In the example above it would be 4   number of pipe characters   1 in the first line   I was thinking something like   awk    FS             print NF   stores dat   but it returns all lines instead of just the first and for the first line it returns 1 instead of 4

User · Answer

you may try   head -1 stores dat   grep -o       wc -l

User · Answer

select any row in the file  in the example below  it s the 2nd row  and count the number of columns  where the delimiter is a space   sed -n 2p text file dat   tr       n    wc -l

User · Answer

awk -F      print NF  exit   stores dat    Just quit right after the first line

User · Answer

Proper pure bash way  Under bash  you could simply   IFS    read -ra headline  lt stores dat echo    headline     4   A lot quicker as without forks  and reusable as  headline hold the full head line  You could  for sample   printf   -  s n     headline       - sid  - storeNo  - latitude  - longitude   Nota This syntax will drive correctly spaces and others characters in column names   Alternative  strong binary checking for max columns on each rows  What if some row do contain some extra columns   This command will search for bigger line  counting separators   tr -dc    n    lt stores dat  wc -L 3   There are max 3 separators  then 4 fields

User · Answer

This is usually what I use for counting the number of fields   head -n 1 file name   awk -F      print NF  exit

User · Answer

Unless you re using spaces in there  you should be able to use   wc -w on the first line   wc is  Word Count   which simply counts the words in the input file  If you send only one line  it ll tell you the amount of columns

User · Answer

Based on Cat Kerr response  This command is working on solaris   awk   print NF  exit   stores dat

User · Answer

Perl solution similar to Mat s awk solution   perl -F     -lane  print   F 1  exit  stores dat   I ve tested this on a file with 1000000 columns     If the field separator is whitespace  one or more spaces or tabs  instead of a pipe   perl -lane  print   F 1  exit  stores dat

User · Answer

This is a workaround  for me  I don t use awk very often    Display the first row of the file containing the data  replace all pipes with newlines and then count the lines     head -1 stores dat   tr       n    wc -l

User · Answer

If you have python installed you could try   python -c  import sys f open sys argv 1   print len f readline   split              stores dat

User · Answer

You could try     cat FILE   awk   print NF

[linux] unix - count of columns in file

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