Re: which is the best command to use

[lina <lina.lastname@gmail.com>]

On Tuesday 27,December,2011 09:51 PM, Tony Baldwin wrote:
> On Tue, Dec 27, 2011 at 09:11:45PM +0800, lina wrote:
> > On Tuesday 27,December,2011 08:57 PM, lina wrote:
> > > Hi,
> > >
> > > I have two questions, wish to get advice,
> > >
> > > Question 1:
> > >
> > > For a series of files:
> > >
> > > cat  a_*.o* | grep "WARNING"
> > >
> > > some file like a_1.o12 has WARNING, but others does not have WARNING
> > >
> > > How can I let grep returns the filename?
> > I wrote a very-low-level and not-work-as-expected one,
> >
> > #!/bin/sh
> >
> > for filename in *.o*
> >
> > do
> > #echo $filename
> > a= cat $filename | grep "WARNING"
> >          if [ a ]
> >          then
> >                  echo $filename
> >          fi
> >
> > done
> for filename in *.o*; do
> if [ grep "WARNING" ];
> 	then echo $filename
> fi
> done

Thanks,
$ ./return_error_filename.sh
./return_error_filename.sh: line 6: [: grep: unary operator expected


$ cat return_error_filename.sh
#!/bin/sh

for filename in *.o*

do
    if [ grep "WARNING" ];
    then
        echo $filename
    fi

done

> ./tony