UNIX for Dummies Questions & Answers

what will the cmd below do?
ls *.[Mm][Pp]3

1 members mentions that to seek all permutations and combinations of the mp3 extension ill have to use curly braces, {} and not, [].
what then will [] do?

In terms of globbing, your command says....

match anything, followed by a period (dot), followed by an upper OR lowercase M, followed by an upper OR lowercase P, followed by the number 3.

You could also use curly brackets (depending on your shell)....

ls *.{mp,Mp,mP,MP}3

This will have the same effect as the command you posted.

Cheers
ZB

thanks for the reply...
n another few if u dont mind...

1.
i tried the command below n the error msg following it was generated.how do u interpret the error msg?

dsadm@punbi1:/apps/dsadm/Practice/abhi/unix/u1> nohup cat a* >
aspen &
[1] 28032
dsadm@punbi1:/apps/dsadm/Practice/abhi/unix/u1>
msgcnt 4 vxfs: mesg 001: vx_nospace - /dev/dsadm/dsadm file system full
(1 block extent)
ksh: aspen: cannot create


2.isnt it true that the 1st word on a cmd line must be a valid Unix command.if yes then how do i explain the cmd below?

bc1 is a file.it has :
2^3
23*2+4

dsadm@punbi1:/apps/dsadm/Practice/abhi/unix> < bc1 > /dev/tty bc
8

50

1. You disk is full and there is no space left to create a new file.

2. This really depends on the shell, but with most shells, a command line like that is ok.

need help with grep :
down below a11,a1s,a1 r files and for ur info,there r other files also with "a" as thier first letter

dsadm@punbi1:/apps/dsadm/Practice/abhi/unix> grep a* a1

a11:this is a copy of a1

a1s:a1 is a1s

a1:a1

dsadm@punbi1:/apps/dsadm/Practice/abhi/unix> grep "a*" a1
this is
a1


plz explain the diffrence bw the two excution?
plz be elaborate..ive been using grep for sometime now but i am completely at a loss explaining the first output

The shell expands a* but not "a*". A good way to see what is happening is to use echo. Try these commands:

echo "a*" a1
echo a* a1

grep would see they same arguments. To grep, the first one is the pattern....the rest are files to search.

need help with grep :
down below a11,a1s,a1 r files and for ur info,there r other files also with "a" as their first letter

dsadm@punbi1:/apps/dsadm/Practice/abhi/unix> grep a* a1

a11:this is a copy of a1

a1s:a1 is a1s

a1:a1

dsadm@punbi1:/apps/dsadm/Practice/abhi/unix> grep "a*" a1
this is
a1


1.
if i assume that in first case the shell expands a* to all files that begin with an a, then why r other files not included in output (they all have some data in them).
also if the a* expands to file names then what pattern am i searching for?

2.
plz explain the diffrence bw the two excution?
plz be elaborate..ive been using grep for sometime now but i am completely at a loss explaining the first output

3.during execution of grep, the " " regulate the shell from interpreting the metachars, so does that mean that in case of grep the interpretation of metachars is done by the KERNEL ???? (unlike in commands like ls * , etc)
if yes then isnt calling them SHELL METAQCHARACTERS a misnomer???


plz be elaborate