Shell Programming and Scripting

Code:

(echo -n 'Header is: '; head -1 file1.txt ; echo -n ' Trailer is: ';  tail -1 file1.txt )> new_file

I tried this but with this command, only trailer is written on the new_file........i.e. only output of last command is there not of previous three commands.......

My bad, i have missed the grouping of the commands. So it should be

Code:

(echo -n 'Header is: '; head -1 file1.txt ; echo -n ' Trailer is: ';  tail -1 file1.txt) > new_file

Dear,

we r back to the problem.........it gives output in 2 lines now.......

Header 1 is: Header Value
Trailer 1 is: Trailer Value


where as i want like this:

Header 1 is : Header value Trailer 1 is: Trailer value


i.e. all 4 in same line.......I guess the command head -1 file1.txt starts new line after it finishes...........

and wen I execute this script:

(echo -n 'Header is: ' ; echo -n head -1 file1.txt ; echo -n ' Trailer is: ' ; echo -n tail -1 file1.txt) > file2


It gives all prints all in one line and does not execute the command of head and tail in this case.....output is :

Header is: head -1 file1.txt Trailer is: tail -1 file1.txt

Finally this should help you. In future it would be better if you tell the full requirement rather than breaking it up.

This is similar to this Header details

Code:

(echo -n 'Header is: ' ; head -1 file1.txt ; echo -n ' Trailer is: ' ;  tail -1 file1.txt) | tr -d '\n' > file2

Code:

awk ' { if ( NR == 1 ) { head=$0 } else { last = $0 } }END{ printf "Header is : %s Trailer is : %s\n", head, last }' filename

Thanks a lot..........it is now working fine with both ways....I shall post in future more requirements and sample output.....sorry for that..........let me check with 100MB file and see the performance in both cases.........