Good Morning Eric! I don't intend to speak on Joe's behalf, but there is a reference you could address which is available here:
http://www.tldp.org/HOWTO/VMS-to-Linux-HOWTO/advanced-topics.html When you get to that page scroll down to section 8.3 Files, Revisited. I'm sure that these specific questions will be addressed quite clearly there. Joe is a great fellow, but I think he may be enjoying Saturday morning by doing something other than addressing this list. Humor aside, the Linux Documentation Project may be something you may want to keep as a link within your browser. Be well... ------------------------------------------------------------------------ Eric Dunbar wrote: > On 08/09/06, Joseph E. Sacco, Ph.D. <[EMAIL PROTECTED]> wrote: > >> Eric, >> >> "> /dev/null 2>&1 " takes any output directed to stdout or stderr and >> redirects it to the bit bucket, /dev/null. >> >> Specifically: >> * redirect stdout to /dev/null >> >> > /dev/null >> >> * redirect stderr to stdout >> >> 2>&1 >> > > Q1: > So, since it's redirected to a 'bit bucket' (euphemism for garbage > can?), does this mean that nothing happens with the redirected > information? > > Q2: > Also, where are the stdout and stderr coming from? From the first > command (the ls in this case) or from the second command? > > Q3: > In '2>&1': > 1. the '2' represents the 'stderr' from ls (or from both)?, > 2. the '>' represents 'redirect', and > 3. the '&1' means append to 1. What is 1? The first argument passed to > the current command (in this case mail)? > > >> A construct like this is often used in a crontab entry. >> >> -Joseph >> > > <snip> > > >> If you use a construct like this in a crontab file, you >> > > Your thought process ended abruptly? > > Thanks for the edumacational posts -- I'm learning lots, > > Eric. > > >> On Fri, 2006-09-08 at 23:17 -0400, Eric Dunbar wrote: >> >>> On 07/09/06, Joseph E. Sacco, Ph.D. <[EMAIL PROTECTED]> wrote: >>> >>>> Of course, a pipe should work, assuming sendmail is running. Here is an >>>> example: >>>> >>>> % ls | mail -s "output of ls" jsacco > /dev/null 2>&1 >>>> >>> Question time: >>> >>> What does the "> /dev/null 2>&1" do? >>> >>> I understand that the | is the 'pipe' and it redirects the output from >>> the first command to the input for the second but what do the >>> following arguments do?: >>> '>' >>> '/dev/null 2' >>> '>&1' >>> >>> When I try: >>> ls | mail -s "output of ls" username > /dev/null 2>&1 >>> >>> and >>> >>> ls | mail -s "output of ls" username >>> >>> I get the same e-mail with either command. >>> >>> Thanks, Eric. >>> > _______________________________________________ > yellowdog-general mailing list > [email protected] > http://lists.terrasoftsolutions.com/mailman/listinfo/yellowdog-general > HINT: to Google archives, try '<keywords> site:terrasoftsolutions.com' > > _______________________________________________ yellowdog-general mailing list [email protected] http://lists.terrasoftsolutions.com/mailman/listinfo/yellowdog-general HINT: to Google archives, try '<keywords> site:terrasoftsolutions.com'
