football.dat

Source <a
href="http://sunsite.tut.fi/rec/riku/soccer_data/tab/93_94/table.eng0.01_02.html">sunsite.tut.fi/rec/riku/soccer_data/tab/93_94/table.eng0.01_02.html</a>

<pre>
       Team            P     W    L   D    F      A     Pts
    1. Arsenal         38    26   9   3    79  -  36    87
    2. Liverpool       38    24   8   6    67  -  30    80
    3. Manchester_U    38    24   5   9    87  -  45    77
    4. Newcastle       38    21   8   9    74  -  52    71
    5. Leeds           38    18  12   8    53  -  37    66
    6. Chelsea         38    17  13   8    66  -  38    64
    7. West_Ham        38    15   8  15    48  -  57    53
    8. Aston_Villa     38    12  14  12    46  -  47    50
    9. Tottenham       38    14   8  16    49  -  53    50
   10. Blackburn       38    12  10  16    55  -  51    46
   11. Southampton     38    12   9  17    46  -  54    45
   12. Middlesbrough   38    12   9  17    35  -  47    45
   13. Fulham          38    10  14  14    36  -  44    44
   14. Charlton        38    10  14  14    38  -  49    44
   15. Everton         38    11  10  17    45  -  57    43
   16. Bolton          38     9  13  16    44  -  62    40
   17. Sunderland      38    10  10  18    29  -  51    40
   -------------------------------------------------------
   18. Ipswich         38     9   9  20    41  -  64    36
   19. Derby           38     8   6  24    33  -  63    30
   20. Leicester       38     5  13  20    30  -  64    28
</pre>

min_diff.sh

#!/bin/sh

# read data from football.dat
sed -n '6,26p' football.dat | \
# check if its data is number, check diff, and check it is minumum or not
awk 'NR==1{min_diff=100} NR>0{if($7 ~ /^[0-9]+$/ && $9 ~ /^[0-9]+$/)diff=$7-$9; if(diff < 0) diff = -diff; if(min_diff > diff)print min_diff=diff;}' | \
# print the minimum value
tail -n 1