[vox-tech] quick, stupid bash question

vox-tech@lists.lugod.org vox-tech@lists.lugod.org
Wed, 29 May 2002 16:11:30 -0400


On Wed, May 29, 2002 at 12:32:45PM -0700, Shawn P. Neugebauer wrote:
> On Wednesday 29 May 2002 12:18 pm, you wrote:
> >   The order of operation of file operators is right to left.
> 
> The order of redirects is left to right.

Shawn,

  That is correct.  I've just done some tests and things are operated
on left to right, my understanding of how things operate is being 
revised...

    Thanks,
      Mike

man bash:
# REDIRECTION
#    Before a command is executed, its input and output may be  redirected
#    using  a  special notation interpreted by the shell.  Redirection may
#    also be used to open and close files for the current shell  execution
#    environment.   The  following  redirection  operators  may precede or
#    appear anywhere within a simple command  or  may  follow  a  command.
#    Redirections  are  processed  in  the order they appear, from left to
#    right.
[...]
#    Note that the order of redirections is significant.  For example, the
#    command
#
#           ls > dirlist 2>&1
#
#    directs  both standard output and standard error to the file dirlist,
#    while the command
#
#           ls 2>&1 > dirlist
#
#    directs only the standard output to file dirlist, because  the  stan­
#    dard error was duplicated as standard output before the standard out­
#    put was redirected to dirlist.