Capturing shell script command output

designflaw · #1 (**permalink**) 03-01-2006

I am trying to check to see if a file exists on a ftp server, well, I know that cant be done, atleast directly, So I came up with this small script

Quote:

check_file

Code:

ftp -n $HOST <<END_SCRIPT
quote USER $USER
quote PASS $PASSWD
cd public_html/crap
dir $FILE
quit
END_SCRIPT

Where the $ variable have corresponding values, so if I run this on the promt as check_file > check.txt, I can then just check the file size for the check.txt file and know if the file exists or not. Well good deal, But I want to do the above check in the same script, for example, something like

Quote:

check_file_improved

Code:

{
ftp -n $HOST <<END_SCRIPT
quote USER $USER
quote PASS $PASSWD
cd public_html/crap
dir $FILE
quit
END_SCRIPT
} > $CHECK_FILE
if $CHECK_FILE = 0 {
  # file does not exist, lets upload the file to the server
  }
else {
  # file exists on the server, rename the file on server before uploading
  }

but somehow, I cannot capture any information into the $CHECK_FILE. Anyone ?

Perderabo · #2 (**permalink**) 03-01-2006

What language you you trying to use? In the bourne, ksh, bash type shells, you do stuff like this:
FILE=/tmp/output.txt
date > $FILE
This does not change the value of FILE. In your first script you are using a here-document. The last line of your script is the end of the here-document. It does not need to be the end of the script. You can keep on going and do more stuff. Go to our FAQ section and read the article on automating ftp jobs. There are a lot of examples there.

designflaw · #3 (**permalink**) 03-01-2006

I am using bourne shell.

I did go on the FAQ site but I dont see an example in which we are trying to capture output generated by a script commands into a variable. Notice the bold S!

. What I mean is, I need to capture output fromt the ftp command dir $FILE as this will tell me if the file exists on the ftp server.

More UNIX and Linux Forum Topics You Might Find Helpful
Thread	Thread Starter	Forum	Replies	Last Post
Capturing output from grpck command on AIX	pdtak	UNIX for Dummies Questions & Answers	2	03-05-2008 02:58 PM
capturing line from script output and appending to a file	wally_welder	Shell Programming and Scripting	6	08-31-2007 04:03 AM
reading command output from shell script	sri b	Shell Programming and Scripting	4	11-16-2006 12:52 AM
Need help capturing pipe to a file in shell script	heinz	Shell Programming and Scripting	6	11-03-2005 08:27 AM
capturing output in script	MizzGail	Shell Programming and Scripting	6	06-02-2004 08:44 AM

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes	Rate This Thread
Switch to Linear Mode Hybrid Mode Switch to Threaded Mode	Rate This Thread:


	Powered by