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# 1  
Old 03-12-2008
code fragment
Hi

I'm looking at some old unix code and, need some help figuring out some of the commands. Here is the line that I'm having trouble with:

echo "$(date) ${0##*/} started" >> $summary.log

I know the first statement prints out the date but, I don't understand the second command on the line ${0##*/} - what is this doing? I know $0 is the script name but, I don't know what the rest of the command should print out. I know this is very old code -- does anyone know what the command ${0##*/} is supposed to echo out?

tia
# 2  
Old 03-13-2008
for me it outputs the current shell.
Wed Mar 12 23:40:00 EDT 2008 bash started
# 3  
Old 03-13-2008
Quote:
Originally Posted by stonemonolith
Hi

I'm looking at some old unix code and, need some help figuring out some of the commands. Here is the line that I'm having trouble with:

echo "$(date) ${0##*/} started" >> $summary.log

I know the first statement prints out the date but, I don't understand the second command on the line ${0##*/} - what is this doing? I know $0 is the script name but, I don't know what the rest of the command should print out. I know this is very old code -- does anyone know what the command ${0##*/} is supposed to echo out?

tia
Try the man pages. Here is what man sh (Section: Parameter Expansion)had to say
Code:
       ${parameter#word}
       ${parameter##word}
              The word is expanded to produce a pattern just as  in  pathname
              expansion.   If  the pattern matches the beginning of the value
              of parameter, then the result of the expansion is the  expanded
              value  of  parameter  with  the  shortest matching pattern (the
              ''#'' case) or the longest matching pattern (the  ''##''  case)
              deleted.  If parameter is @ or *, the pattern removal operation
              is applied to each positional parameter in turn, and the expan-
              sion  is the resultant list.  If parameter is an array variable
              subscripted with @ or  *,  the  pattern  removal  operation  is
              applied  to each member of the array in turn, and the expansion
              is the resultant list.

In your case, $0 would translate to the current shell's path. Like /bin/bash or /bin/ksh or /usr/bin/sh or whichever it is.
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