problem running grep within system command in perl

[jeniffer]

system("nm -r *.o|grep -v '.o' |grep "T\|t\|U\|u" |cut -c 12-|sort|
uniq"); the problem is that if we match 1 or more strings in grep the
argument must be in quotes i.e T\|t\|U\|u must be withing quotes ...how
do i escape them so that the above works fine?

 

[John Bokma]

system("nm -r *.o|grep -v '.o' |grep "T\|t\|U\|u" |cut -c 12-|sort|
uniq"); the problem is that if we match 1 or more strings in grep the
argument must be in quotes i.e T\|t\|U\|u must be withing quotes ...how
do i escape them so that the above works fine?

system('nm -r *.o|grep -v '.o' |grep "T\|t\|U\|u" |cut -c 12-|sort|

uniq')

system("nm -r *.o|grep -v '.o' |grep \"T\|t\|U\|u\" |cut -c 12-|sort|

uniq")

system( qq(nm -r *.o|grep -v '.o' |grep "T\|t\|U\|u" |cut -c 12-|sort|

uniq") )

I would use the fist one.

 

[A. Sinan Unur]

Is that an inflated ego or what?

system("nm -r *.o|grep -v '.o' |grep "T\|t\|U\|u" |cut -c 12-|sort|
uniq"); the problem is that if we match 1 or more strings in grep the
argument must be in quotes i.e T\|t\|U\|u must be withing quotes ...how
do i escape them so that the above works fine?

perldoc perlop

Look for "Quote and Quote-like Operators"

Sinan

 

[John W. Krahn]

system("nm -r *.o|grep -v '.o' |grep "T\|t\|U\|u" |cut -c 12-|sort|
uniq"); the problem is that if we match 1 or more strings in grep the
argument must be in quotes i.e T\|t\|U\|u must be withing quotes ...how
do i escape them so that the above works fine?

open PIPE, 'nm -r *.o |' or die "Cannot open pipe from nm $!";

my %data;
while ( <PIPE> ) {
next if /\.o/;
next unless /[tu]/i;
$data{ substr $_, 12 } = ();
}

close PIPE or warn $! ? "Error closing nm pipe: $!"
: "Exit status $? from nm";

print sort keys %data;


John

 

[John W. Krahn]

system("nm -r *.o|grep -v '.o' |grep "T\|t\|U\|u" |cut -c 12-|sort|
uniq"); the problem is that if we match 1 or more strings in grep the
argument must be in quotes i.e T\|t\|U\|u must be withing quotes ...how
do i escape them so that the above works fine?

open PIPE, 'nm -r *.o |' or die "Cannot open pipe from nm $!";

my %data;
while ( <PIPE> ) {
next if /\.o/;
next unless /[tu]/i;
$data{ substr $_, 12 } = ();
}

close PIPE or warn $! ? "Error closing nm pipe: $!"
: "Exit status $? from nm";

print sort keys %data;

And to avoid any shell interaction:

my $prog = 'nm';
my @switches = qw[ -r ];
my @files = glob '*.o';

open PIPE, '-|', $prog, @switches, @files
or die "Cannot open pipe from $prog $!";

my %data;
while ( <PIPE> ) {
next if /\.o/;
next unless /[tu]/i;
$data{ substr $_, 12 } = ();
}

close PIPE or warn $! ? "Error closing $prog pipe: $!"
: "Exit status $? from $prog";

print sort keys %data;



John