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Header lines 
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It is a standard problem: you have a data file with header. You want to
manipulate the data file (e.g. sort on a column) but not the header line.


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Ia. Adding a header line to a date file (table.dat)
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$ echo -e "Column:RA Column:Dec Column:Mag" | cat - table.dat  > table_with_hdr
$ sed '1i Column:RA Column:Dec Column:Mag' table > table_with_hdr

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Ib. Replace table.dat with a file which has header
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$ sed -it '1i Column:RA Column:Dec Column:Mag' table
$ echo -e "Column:RA Column:Dec Column:Mag" | cat - table.dat | tee table.dat
	(quite clever and not obvious)

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II. Analyze whilst ignoring header
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Assume that table.dat has a header line. Say you wanto numerically
reverse sort on column 1.

$ head -n 1 table.dat  && tail -n +2 table | sort -nr -k1 
$ head -n1 table.dat; tail -n +2 table | sort -nr -k1

$ awk 'NR<2{print $0;next}{print $0| "sort -nr -k1"}'
$ awk'NR==1;NR>1{print $0| "sort -nr -k1"}'

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III. The BEST solution 
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$ cat a.dat
Header
1
2
3

$ (header -n1; sort -knr)<a.dat      #elegant, key stroke saved 
Header
3
2
1