understanding external filter stage

[vamsi_4a6]

The output of external filter stage is not clear in below link.

http://www-01.ibm.com/support/docview.w ... wg21597213


I know what tr command will do but still it is not clear

[rkashyap]

External filter stage is not able to handle special characters, like square brackets, escape character etc which are quite often present in value of "argument" property.

In the link given in post above ... following workaround is suggested to above mentioned bug:
1. Write "tr's" argument (which contains special characters) to Unix file " /tmp/a1".
2. Pass the content of above mentioned Unix file to "argument property" of External Filter stage by using 'cat' command in backquote/backtick.

[vamsi_4a6]

what i am asking is what is the output of exernal filter stage i mean what is the output of following command

tr `cat/tmp/a1`

[chulett]

I thought you said you knew what the tr command does.

The example linked to was extremely generic so what exactly happens depends on what is in a1, i.e. 'the content of the argument'.

[vamsi_4a6]

i have refereed below link for tr command

http://www.softpanorama.org/Tools/tr.shtml.

In all examples in above link we are using some flag like -c,-d but in lBM link in my original post we did not use any flag

[chulett]

Those are called options for a reason.

[vamsi_4a6]

what will happen without using any options.i mean if we pass only filename to tr command

[chulett]

You need to look closer at the example. They are not simply passing 'only filename' to the command, the contents of the file are being cat'd to the command. And we have no idea what exactly is in the file (other than whatever 'special characters' were being passed on the command line that was causing a problem) as it's not really critical to understanding the workaround they posted.

Why not simply experiment, play with the command yourself?