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'
