parse http response header from wget

Question

Im trying to extract a line from wget's result but having trouble with it. This is my wget call:

$ wget -SO- -T 1 -t 1 http://myurl.com:15000/myhtml.html

Output:

--18:24:12--  http://xxx.xxxx.xxxx:15000/myhtml.html
           => `-'
Resolving xxx.xxxx.xxxx... xxx.xxxx.xxxx
Connecting to xxx.xxxx.xxxx|xxx.xxxx.xxxx|:15000... connected.
HTTP request sent, awaiting response...
  HTTP/1.1 302 Found
  Date: Tue, 18 Nov 2008 23:24:12 GMT
  Server: IBM_HTTP_Server
  Expires: Thu, 01 Dec 1994 16:00:00 GMT
  Location: https://xxx.xxxx.xxxx/siteminderagent/...
  Content-Length: 508
  Keep-Alive: timeout=10, max=100
  Connection: Keep-Alive
  Content-Type: text/html; charset=iso-8859-1
Location: https://xxx.xxxx.xxxx//siteminderagent/...
--18:24:13--  https://xxx.xxxx.xxxx/siteminderagent/...
           => `-'
Resolving xxx.xxxx.xxxx... failed: Name or service not known.

if I do this:

$ wget -SO- -T 1 -t 1 http://myurl.com:15000/myhtml.html | egrep -i "302" <br/>

It doesnt return me the line that contains the string. I just want to check if the site or siteminder is up.

Answer 1

The output of wget you are looking for is written on stderr. You must redirect it:

$ wget -SO- -T 1 -t 1 http://myurl.com:15000/myhtml.html 2>&1 | egrep -i "302" 

Answer 2

wget prints the headers to stderr, not to stdout. You can redirect stderr to stdout as follows:

wget -SO- -T 1 -t 1 http://myurl.com:15000/myhtml.html 2>&1 | egrep -i "302"

The "2>&1" part says to redirect ('>') file descriptor 2 (stderr) to file descriptor 1 (stdout).

Answer 3

A bit enhanced version of already provided solution

wget -SO- -T 1 -t 1 http://myurl.com:15000/myhtml.html 2>&1 >/dev/null | grep -c 302

2>&1 >/dev/null will trim off unneeded output. This way egrep will parse only wget`s stderr, what eliminates possibility to catch strings containing 302 from stdout (where html file itself outputted + download proces bar with resulting bytes count e.t.c.) :)

egrep -c counts number of matched strings instead of simply output them. Enough to know how much strings egrep matched.