On Tuesday 27 Sep 2011, Sagar Belure wrote: > Can anyone describe what exactly is happening here: > user@linux:~$ cat << __eof > test.txt > > > anything > > Anything > > AnyThing > > ANYTHING > > __eof > > user@linux:~$ cat test.txt > anything > Anything > AnyThing > ANYTHING > user@linux:~$ cat << anything > test2.txt > > > apple > > bat > > cat > > dog > > anything > > user@linux:~$ cat test2.txt > apple > bat > cat > dog > user@linux:~$ > > I really have poor understanding of things happening, but I used this > method couple of times to write in a file without using any editor. > So, I would be really happy if someone can explain that in detail, > or point me to some appropriate place for this.
The general format is: command <<SOMESTRING line-1 line-2 ... line-n SOMESTRING Everything between the command line and the next occurance of SOMESTRING on a line by itself is treated as standard input to command, just as if you'd run the command, typed in lines 1 through n manually and pressed ^d . The main drawback, of course, is that you cannot give a line containing just SOMESTRING as part of the input -- the moment the shell sees that, it treats it as end of input. In your second example, SOMESTRING == anything, so the here document is terminated when you type that in. For more detailed information, look up "shell here documents" on the 'net. Regards, -- Raj -- Raj Mathur r...@kandalaya.org http://kandalaya.org/ GPG: 78D4 FC67 367F 40E2 0DD5 0FEF C968 D0EF CC68 D17F PsyTrance & Chill: http://schizoid.in/ || It is the mind that moves -- You received this message because you are subscribed to the Google Groups "ILUG Bengaluru" group. To post to this group, send email to ilug-bengaluru@googlegroups.com. To unsubscribe from this group, send email to ilug-bengaluru+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/ilug-bengaluru?hl=en.
