bob@dhw68k.cts.com (Bob Best) (07/19/88)
This script implements the functionality of cut(1).
In testing it, I seem to have discovered a limitation, if not a bug,
of the perl 'foreach' command (see under 'BUG' below).
This script has NOT been thoroughly tested.
----------cut here----------
#!/bin/perl
#
# perl version of cut(1)
# written by bob best (bob@dhw68k.cts.com)
# Mon Jul 18 15:52:02 PDT 1988
#
# to use space character as delimiter, backslash single quotes (-d\' \')
#
# the use of an unbounded upper range in -f or -c option assumes
# limit of 512 fields
#
# unlike cut(1), this script lists fields in the specified order
#
# unlike cut(1), this script is SLOW!
#
eval "exec /bin/perl -S $0 $*"
if $running_under_some_shell;
$MAXFIELDS='512';
$delimiter="\t";
while ($_ = $ARGV[0], /^-/) {
shift;
/^-c(.*)/ && ($clist=$1);
/^-f(.*)/ && ($flist=$1);
/^-d(.)/ && ($delimiter=$1);
/^-s/ && ($suppress=1);
}
if ($clist eq '' && $flist eq '') {die "must specify either -c or -f, aborting";}
if ($clist ne '' && $flist ne '') {die "specify -c or -f but not both, aborting";}
if ($flist) {$_=$flist;} else {$_=$clist;}
while (/(\d*)-(\d*)/) {
if ($1) {$x=$1;} else {$x=1;}
if ($2) {$y=$2;} else {$y=$MAXFIELDS;}
for ($i=$x+1;$i<=$y;$i++) {
$x .= ",$i";
}
s/$&/$x/;
}
$list=$_;
@list=split(/,/,$list);
$[=1;
line: while (<>) {
chop;
if ($clist) {
split(//);
}
else {
#perl doesn't handle null, space delimited, fields without this
$delimiter eq ' ' ? split(/ /) : split(/$delimiter/);
}
goto line if ($suppress && $#_==1);
$cut='';
foreach $i (@list) {
#BUG: if foreach loop terminates early (via 'last' or 'next line')
# VAR i is not reset to first element in ARRAY list
# therefore, must cycle through the entire foreach loop
# hence, unable to use the following lines:
# last if $i > $#_;
# next line if $i > $#_;
next if $i > $#_;
$cut .= $_[$i];
$cut .= $delimiter if $flist;
}
}
continue
{
chop($cut) if $flist; #remove trailing delimiter
print "$cut\n";
}
--
Bob Best
uucp: ...{trwrb,hplabs}!felix!dhw68k!bob InterNet: bob@dhw68k.cts.com