Unix Questions & Answers - Part 2

[wacky]

6) How would you remove blank lines from a file?

grep "^$" filename > filename.new

Can also use sed and awk

7) How would you list the files in the current directory sorted by size?

ls -l | sort -k 5 -n[r]

8) How would you display the routing table?

netstat -r

9) What is a sparse file. Give a common example of it being used?

A record based file where the contents may be written to certain offsets
based on the record number and the record structures length. This could
mean that the file appears larger than it actually is , this is normally
achieved using system calls such as fseek() and fsetpos().

lastlog & coredumps are typical examples.

10) How would you find the time/date of the last reboot?

who -b

Please feel free to comment on any of this.

[ranatanveer]

ok waiting for.

[LinuxFreaK]

Dear wacky,
Salam,

6) How would you remove blank lines from a file?

You can use either sed, grep for this purpose.

# sed '/^$/d' file > newfile

or

# grep -v '^$' file > newfile

7) How would you list the files in the current directory sorted by size?

# ls -lS

How would you display the routing table?

# route -n

9) What is a sparse file. Give a common example of it being used?

Not sure about that ...

10) How would you find the time/date of the last reboot?

# uptime

or

# w

Please don't post your answers here. I'll put the answers here in a couple of days' time.

I saw this after writing whole post so i think i should let it go.

Best Regards.