Using commands in scripts

Karas · 11-23-2009, 11:30 AM

Hi all, I am just wondering how to use commands inside of a script.

In the code below, names is a variable.

Quote:

names=cat newusers.txt | cut -f1 -d":"

For some reason the cat command doesn't work, am I missing some characters?

Thanks.

mail4vijay · 11-23-2009, 11:39 AM

Quote:

Originally Posted by Karas

Hi all, I am just wondering how to use commands inside of a script.

In the code below, names is a variable.

For some reason the cat command doesn't work, am I missing some characters?

Thanks.

Tickes are missing.. use with

Quote:

names=`cat newusers.txt | cut -f1 -d":"`

rweaver · 11-23-2009, 11:39 AM

Quote:

Originally Posted by Karas

Hi all, I am just wondering how to use commands inside of a script.

In the code below, names is a variable.

For some reason the cat command doesn't work, am I missing some characters?

Thanks.

You're missing the ` character (unshifted ~ key, over by the 1)

Code:

names=`cat newusers.txt | cut -f1 -d":"`

chrism01 · 11-23-2009, 04:53 PM

IOW, generically

x=a b c

means assign 'a b c' to x

x=`a b c`
means run the cmd a

x=$(a b c )

is the same.

Have a look at these
http://rute.2038bug.com/index.html.gz
http://tldp.org/LDP/Bash-Beginners-G...tml/index.html
http://www.tldp.org/LDP/abs/html/

pixellany · 11-23-2009, 05:11 PM

"Tickes" (actually back-tics) are deprecated. The preffered usage is $(<command-string>)

Speaking to the thread title: Commands in scripts are the same as those typed in a terminal..the only difference is that--in a terminal--a long sequence of commands needs to be separated by ";"s (or use a "here document".)

You can enter commands one at a time and verify how they work---then combine them in a script.

catkin · 11-23-2009, 10:21 PM

Quote:

Originally Posted by pixellany

"Tickes" (actually back-tics) are deprecated. The preffered usage is $(<command-string>)

For reasons explained here.

i92guboj · 11-23-2009, 10:27 PM

Unless you require compatibility with the original bourne shell, since $() is a bashism.