The method of variable passing between awk and Shell

The method of variable passing between awk and Shell

awk is a good thing to do with Linux, and it's very handy to work with some text files. under Linux, it's often the case that you deal with the shell , so the variables between awk and The shell are sometimes necessary, so simply summarize.

awk use shell in the variables in

one , "' $var '"

In this way, you don't have to change the habit of using the awk program, which is commonly used by foreigners . such as :

var= "Test"
awk ' begin{print ' $var ' "} '

This notation is actually a constant that is double-parenthesis into parentheses , passed to awk.

if the var contains spaces , in order for the shell not to use the space as a sub-Geff , it should be used as follows :

Var= "This is a test"
awk ' Begin{print ' "$var" ' "} '
two . ' $var '

This is similar to the previous one . If the variable contains spaces , it becomes ' "" $var "" is more reliable .
Export variable , using environ["var" form , Get the value of an environment variable

For example :
Var= "This is a test"; Export var;

awk ' Begin{print environ["var"]} '
Four, You can use awk the- v Options (if the number of variables is not many, personal preference for this type of writing)

For example :
Var= "This is a test"
Awk-v awk_var= "$var" ' BEGIN {print Awk_var} '

This then passes the system variable var to the awk variable awk_var.

awk to the shell Variable Pass value

The idea of passing a variable from awk to the shell is nothing more thanusing awk (Sed/perl and so on ) to output several strips Shell Command, and then use the shell to execute the commands.

Eval $ (awk ' begin{print ' var1= ' str1′;var2= ' str2′ "} ')

or eval $ (awk ' {printf ("var1=%s; var2=%s; var3=%s; ", $1,$2,$3)} ' Abc.txt)

Variables such as Var1,var2 can then be used in the current shell .

echo "var1= $var 1-–var2= $var 2″

Resources:

Http://developer.51cto.com/art/200509/3781.htm

Http://www.ixpub.net/thread-1457438-1-1.html

This article is from the "Cool bit Linux" blog, so be sure to keep this source http://coolbyte.blog.51cto.com/8289854/1687609

The method of variable passing between awk and Shell