Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.debian.user > #173807

Re: bash NEWBIE I/O and I/O redirection problems

Show all headers | View raw

[Multipart message — attachments visible in raw view] - view raw

Am 24. Oct, 2016 schwätzte Richard Owlett so:

moin moin Richard,

"to stdout AND "logfile" can be accomplished with tee.

# puts the results of ls in the file and also shows results on STDOUT
# the -a tells tee to append so repeated calls will get all of the output
# from your script
ls | tee -a /tmp/ls.out

By default tee truncates so without the -a it will first zero out the
file, then start adding text.

$ rm /tmp/ls.out
$ ls -l /etc/issue | tee -a /tmp/ls.out; ls -l /tmp/ls.out
-rw-r--r-- 1 root root 26 Nov 30  2014 /etc/issue
-rw-r--r-- 1 lufthans lufthans 50 Okt 24 20:06 /tmp/ls.out
$ ls -l /etc/issue | tee -a /tmp/ls.out; ls -l /tmp/ls.out
-rw-r--r-- 1 root root 26 Nov 30  2014 /etc/issue
-rw-r--r-- 1 lufthans lufthans 100 Okt 24 20:06 /tmp/ls.out
$ ls -l /etc/issue | tee /tmp/ls.out; ls -l /tmp/ls.out
-rw-r--r-- 1 root root 26 Nov 30  2014 /etc/issue
-rw-r--r-- 1 lufthans lufthans 50 Okt 24 20:06 /tmp/ls.out
$

ciao,

der.hans

> I suspect an appropriate response would be being pointed an *atypical* 
> tutorial.
> A Google search for "bash tutorial pipe redirect" [w/o quotes] gave results 
> for "normal" users. I have and odd use case. I had assumed bash as shell but 
> am open to using another shell if it is more appropriate.
>
> The following, though using bash syntax, should be considered *PSEUDO* code.
>
> # stdout and stderr will be a MATE terminal window
> # this was required to address a problem outside scope of this post
> gsettings set org.mate.media-handling automount false
>
>
> while true
>  do
>    echo "Insert medium, press Enter key (or Ctrl+C to end)"
>    read dummyvar
> # need code here for /dev/sr0 to be "ready" - I had been watching drive 
> activity light
>    blocks=$(expr $(/sbin/isosize /dev/sr0) / 2048)
>    echo "Block count: "$blocks 		;# to stdout AND "logfile"
>    echo "Byte count: $(expr $blocks '*' 2048)" ;# to stdout AND "logfile"
>    DEVICEBLKCOUNT=$(expr $(cat /sys/class/block/sr0/size) / 4)
>    echo "Device block count: "$DEVICEBLKCOUNT	;# to stdout AND "logfile"
>    echo ""					;# to stdout AND "logfile"
>    echo "*********************"		;# to stdout ONLY
>    echo "The output file will be $FILENAME"	;# to stdout AND "logfile"
>    xorriso -indev /dev/sr0  -data_cache_size 512 1024 -check_media 
> data_to=$FILENAME
>    echo ""					;# to stdout AND "logfile"
>    echo "next lines are output of ls and isosize commands" ;# to stdout ONLY
>    ls -l $FILENAME				;# to stdout AND "logfile"
>    /sbin/isosize $FILENAME			;# to stdout AND "logfile"
>    echo "about to repeat loop"			;# to stdout ONLY
>    echo ""					;# to stdout AND "logfile"
>  done
>
>

-- 
#  http://www.LuftHans.com/        http://www.PhxLinux.org/
#  "It's not that I'm so smart, it's just that I stay with problems longer."
#  -- Albert Einstein

Back to linux.debian.user | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

bash NEWBIE I/O and I/O redirection problems Richard Owlett <rowlett@cloud85.net> - 2016-10-25 04:30 +0200
  Re: bash NEWBIE I/O and I/O redirection problems "der.hans" <deb-user@LuftHans.com> - 2016-10-25 05:10 +0200
    Re: bash NEWBIE I/O and I/O redirection problems "Thomas Schmitt" <scdbackup@gmx.net> - 2016-10-25 09:30 +0200
      Re: bash NEWBIE I/O and I/O redirection problems "Thomas Schmitt" <scdbackup@gmx.net> - 2016-10-25 11:30 +0200
    Re: bash NEWBIE I/O and I/O redirection problems Richard Owlett <rowlett@cloud85.net> - 2016-10-25 14:20 +0200
  Re: bash NEWBIE I/O and I/O redirection problems <tomas@tuxteam.de> - 2016-10-25 11:30 +0200
    Re: bash NEWBIE I/O and I/O redirection problems Richard Owlett <rowlett@cloud85.net> - 2016-10-25 14:20 +0200
  Re: bash NEWBIE I/O and I/O redirection problems Greg Wooledge <wooledg@eeg.ccf.org> - 2016-10-25 14:10 +0200

csiph-web