#-------------------------------------shell-------------------------------------
PS1='$PWD> '           # prompt showing current directory
PATH=$PATH':whatever'  # append to path
cd -                   # previous directory

#-------------------------------------date-------------------------------------
date -v-7H "+%A %l:%M:%S %p, %Y-%m-%d"   # Friday  3:59:50 PM, 2003-09-12 ( -7 hours from GMT specified )
date +"%Y-%m-%d-%H-%M"                   # 2005-11-09-13-19

#-------------------------------------tar-------------------------------------
# tar -c create, -x extract, -f file, -v verbose
  tgz: tar -cvf - $* | gzip > my.tgz       # "-" alone important 
untgz: gunzip -c my.tgz | tar -xvf -

#-------------------------------------scripts-------------------------------------
for ((x=1;x<20000;x++)); do clear; ls -al; sleep 5; done    # for (c-style) loop
for i in $* ; do echo $i; done;        # for-in loop; all ARGV command line arguments 

#-------------------------------------strings-------------------------------------
echo "Make LOWERCASE" |  tr A-Z a-z # convert from uppercase to lowercase
ls -w | sed s/www.robertbody.com./RB:/              # replace "www...com" with "RB:"

#-------------------------------------scripts-------------------------------------
tail -200 file* | grep -B1 redirect
ls -w | sed s/www.robertbody.com./RB:/

for i in $* ; do
  if [ -a $i ]; then               # if file exists (specified as parameters)
    echo "$H $i <-- ok";
  else
    echo "$H $i <-- does not exist"; allFound=0;
  fi;
done;
#-------------------------------login script example------------------------------
/www/robertbody/robertbody.com> cat r
echo "...robertbody setup..."
echo "   PS1='\$PWD> '"
echo " MYBIN=/www/robertbody/robertbody.com/cgi-bin/bin"
echo "     C=/www/robertbody/robertbody.com/cgi-bin/counter"
echo "  PATH=.:\$PATH:\$MYBIN"
echo "......................"
PS1='$PWD> '
MYBIN=/www/robertbody/robertbody.com/cgi-bin/bin
C=/www/robertbody/robertbody.com/cgi-bin/counter
PATH=.:$PATH:$MYBIN