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problem in executing shell script

开发者 https://www.devze.com 2023-03-13 10:03 出处:网络
i am new to shell scripting. My objective is 开发者_开发知识库to execute the ls command through a shell script but it does not return anything. Mine is a BASH shell

i am new to shell scripting. My objective is 开发者_开发知识库to execute the ls command through a shell script but it does not return anything. Mine is a BASH shell

set p = `/bin/ls`
echo $p

Where am i going wrong


For bash the way to do it is

p="$(/bin/ls)"
# Could have done p=`/bin/ls` too, but $( is the newer way
echo "$p"

The set command is not for standard variable assignment.


A simple

p=`/bin/ls`

will suffice although I prefer the $() construct since it's easily nestable:

pax$ p=$(/bin/ls)

pax$ echo $p
clients.dat clientupdate.sh

What your set does (after processing all the valid switches to set shell attributes, of which there are none) is to assign the parameters to the $n arguments:

pax$ set p = `/bin/ls`

pax $ echo xx $1 xx $2 xx $3 xx $4 xx $5
xx p xx = xx clients.dat xx clientupdate.sh xx xx

From the man bash_builtins page:

Any arguments remaining after the options are processed are treated as values for the positional parameters and are assigned, in order, to $1, $2, ... $n.


The Bash syntax is to not put in spaces when assigning values to variables, so do it like this:

p=`/bin/ls`
echo $p


Can't you just write...

/bin/ls

...in one line?

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