question on redirection (<<) Post: 302072471

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Top Forums Shell Programming and Scripting question on redirection (<<) Post 302072471 by x96riley3 on Wednesday 3rd of May 2006 10:16:08 AM

05-03-2006

Registered User

I've been looking at this and I don't understand cat << BAR myself. I've done some testing using this construct and it fails. I get nothing out of trying this. Where is BAR coming from anyways? Here is the rest

/tmp# echo 'hello world' > rootfile #print the string 'hello world into a new file called rootfile
/tmp# chmod 600 rootfile # change the perms to be -rw-------(Read and write by the owner only)
/tmp# ln -s rootfile sh$$ #Create a symbolic link. $$ means session id number. So link sh$$ with rootfile. If I vi sh$$ it's the same as doing a vi rootfile because they are linked.
/tmp# chown -h 666.666 sh$$ # -h means change if it's a symbolic link which it is. The uid and gid are being changed to 666
/tmp# ls -l rootfile sh$$ #Do a long list of both files
-rw------- 1 root root 12 Oct 29 03:55 rootfile
lrwxrwxrwx 1 666 666 8 Oct 29 03:56 sh12660 -> rootfile
/tmp# cat <<BAR # Have no idea, where is BAR coming from?
? FOO
? BAR
FOO
o world
/tmp# ls -l rootfile sh$$ # Do a long list of both files again, yet the link file is now missing after running the cat <<BAR command.
/bin/ls: sh12660: No such file or directory
-rw------- 1 root root 12 Oct 29 03:56 rootfile
/tmp# cat rootfile #Show contents of rootfile.
FOO
o world
/tmp#

Wish I could be more helpful.

-X

x96riley3

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LEARN ABOUT DEBIAN

flow-cat

flow-cat(1)						      General Commands Manual						       flow-cat(1)

NAME

       flow-cat -- Concatenate flow files

SYNOPSIS

       flow-cat  [-aghmp]   [-b  big|little]   [-C  comment]   [-d  debug_level]   [-o	filename]   [-t start_time]  [-T start_time]  [-z z_level]
       [file|directory ...]

DESCRIPTION

       The flow-cat utility processes files and/or directories of files in the flow-tools format.  The resulting concatenated data set is  written
       to the standard output or file specified by -o.	If file is a single dash (`-') or absent, flow-cat will read from the standard input.

OPTIONS

       -a	 Do not ignore filenames that begin with tmp.

       -b big|little
		 Byte order of output.

       -C Comment
		 Add a comment.

       -d debug_level
		 Enable debugging.

       -g	 Sort file list by capture start time before processing.

       -h	 Display help.

       -m	 Disable the use of mmap().

       -p	 Preload headers.  Use to preserve meta information such as lost flows.

       -o file	 Write to file instead of the standard out.

       -t start_time
		 Select flow files up to start_time.  If used with -T select files between start_time and end_time.

       -T end_time
		 Select flow files after end_time.  If used with -t select files between start_time and end_time.

       -z z_level
		 Configure compression level to  z_level.  0 is disabled (no compression), 9 is highest compression.

       file|directory...
		 Process the files and/or directory.

TIME
/DATE parsing
       start_time  and	end_time  parsing  is  implemented with getdate.y, a commonly used function to process free-form time date specifications.
       Example usage borrowed from cvs:
	   1 month ago
	   2 hours ago
	   400000 seconds ago
	   last year
	   last Monday
	   yesterday
	   a fortnight ago
	   3/31/92 10:00:07 PST
	   January 23, 1987 10:05pm
	   22:00 GMT

EXAMPLES

       Concatenate all flow files begining with ft-v05.2001-05.01, use flow-print to display the results.

	   flow-cat ft-v05.2001-05-01.* | flow-print

       Concatenate flow files in /flows/krc4, store store the output in compressed.flows at compression level 9 (best).  The headers are preloaded
       so  various  metadata  such  as	the flow count is correct in the result.  Filenames begining with tmp which are typically in-progress flow
       files from flow-capture are not processed.

	   flow-cat -p -z9 /flows/krc4 > compressed.flows

BUGS

       None known.

AUTHOR

       Mark Fullmer maf@splintered.net

SEE ALSO

       flow-tools(1)

																       flow-cat(1)

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