Duplicate output without tee

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Mindboggling difference between using "tee" and "/usr/bin/tee" in bash

I'm on Ubuntu 14.04 and I manually updated my coreutils so that "tee" is now on version 8.27 I was running a script using bash where there is some write to pipe error at some point causing the tee command to exit abruptly while the script continues to run. The newer version of tee seems to prevent...

2. Shell Programming and Scripting

Trying to get rid of a duplicate output line...

Hi folks, I'm trying to work on a script that will grab a router interface report and generate the numbers of "in use" and "un-used" ports per device. Right now, I've got a cut down of the report as follows: sing /usr/apps/siteName/etc/DCAFT-9K.cmds for send text Connecting using...

3. Shell Programming and Scripting

Duplicate files and output list

Gents, I have a file like this. 1 1 1 2 2 3 2 4 2 5 3 6 3 7 4 8 5 9 I would like to get something like it 1 1 2 2 3 4 5 3 6 7 Thanks in advance for your support :b:

4. Shell Programming and Scripting

Screen output is blocked by "| tee" command

BACK STORY: I have a script build.py . (It's for creating the ISO file for a special edition of Swift Linux.) This build.py script executes the mintConstructor.py script that I use to modify the Regular Swift Linux ISO to get the special edition Swift Linux ISO. The lines of the script that...

5. Shell Programming and Scripting

how to duplicate an output in shell script

how to duplicate an output from a shell command? for example: `date` will give the current date to the console. I want this to be displayed in console and also parallely store it in file or variable. user1@solaris4:~> date Tue Feb 28 17:48:31 EST 2012 user1@solaris4:~> date > file ...

6. Shell Programming and Scripting

problem with suppressed output to file using echo and tee command

Hi, When I run the following command in terminal it works. The string TEST is appended to a file silently. echo TEST | tee -a file.txt &>/dev/null However, when I paste this same line to a file, say shell1.sh, and use bourne shell . I run this file in terminal, ./shell1.sh. However I...

7. UNIX for Dummies Questions & Answers

tee vs output redirection confusion

ok, suppose i have a file called f1 $ cat f1 this is file1 the quick brown fox jumped over the lazy dog this is file1 who let the dogs out this is unix this is file1 and i have another file f2 $ cat f2 this is file2 the task is to eliminate the repeated lines in f1 and add the...

8. Shell Programming and Scripting

How Unix tee to send pipeline output to 2 pipes ?

Hi, I would like to process, filter the same ASCII asynchronous live data stream in more than one pipe pipeline. So the one pipeline should filter out some records using grep key word and more than one pipes pipelines each should grep for another key words, each set seperately for each...

9. Shell Programming and Scripting

log script input and output using tee ?

hi, new to to forum... i've been trying to create a script in tcsh but i'm having a problem with one thing... the script has to keep log of it's input and output so i'm using tee -a log | script | tee -a log this keeps the logs as asked, but it gives me an extra empty prompt (not in the...

10. Shell Programming and Scripting

'tee' STDERR output (ksh)

Hi everyone, KSH question: I know you can 'tee' STDOUT to have the output go to multiple targets; can you do the same with STDERR? For example: ls |tee /tmp/file.txt Will redirect STDOUT to both the screen and the '/tmp/file.txt' file. Is there a way of doing the same thing for...

LEARN ABOUT LINUX

tee

TEE(2)							     Linux Programmer's Manual							    TEE(2)

NAME

       tee - duplicating pipe content

SYNOPSIS

       #define _GNU_SOURCE
       #include <fcntl.h>

       ssize_t tee(int fd_in, int fd_out, size_t len, unsigned int flags);

DESCRIPTION

       tee()  duplicates  up  to  len  bytes  of  data	from the pipe referred to by the file descriptor fd_in to the pipe referred to by the file
       descriptor fd_out.  It does not consume the data that is duplicated from fd_in;	therefore,  that  data	can  be  copied  by  a	subsequent
       splice(2).

       flags is a series of modifier flags, which share the name space with splice(2) and vmsplice(2):

       SPLICE_F_MOVE	  Currently has no effect for tee(); see splice(2).

       SPLICE_F_NONBLOCK  Do not block on I/O; see splice(2) for further details.

       SPLICE_F_MORE	  Currently has no effect for tee(), but may be implemented in the future; see splice(2).

       SPLICE_F_GIFT	  Unused for tee(); see vmsplice(2).

RETURN VALUE

       Upon successful completion, tee() returns the number of bytes that were duplicated between the input and output.  A return value of 0 means
       that there was no data to transfer, and it would not make sense to block, because there are no writers connected to the write  end  of  the
       pipe referred to by fd_in.

       On error, tee() returns -1 and errno is set to indicate the error.

ERRORS

       EINVAL fd_in or fd_out does not refer to a pipe; or fd_in and fd_out refer to the same pipe.

       ENOMEM Out of memory.

VERSIONS

       The tee() system call first appeared in Linux 2.6.17.

CONFORMING TO

       This system call is Linux-specific.

NOTES

       Conceptually,  tee()  copies  the  data between the two pipes.  In reality no real data copying takes place though: under the covers, tee()
       assigns data in the output by merely grabbing a reference to the input.

EXAMPLE

       The following example implements a basic tee(1) program using the tee() system call.

       #define _GNU_SOURCE
       #include <fcntl.h>
       #include <stdio.h>
       #include <stdlib.h>
       #include <unistd.h>
       #include <errno.h>
       #include <limits.h>

       int
       main(int argc, char *argv[])
       {
	   int fd;
	   int len, slen;

	   if (argc != 2) {
	    fprintf(stderr, "Usage: %s <file>
", argv[0]);
	    exit(EXIT_FAILURE);
	   }

	   fd = open(argv[1], O_WRONLY | O_CREAT | O_TRUNC, 0644);
	   if (fd == -1) {
	       perror("open");
	       exit(EXIT_FAILURE);
	   }

	   do {
	       /*
		* tee stdin to stdout.
		*/
	       len = tee(STDIN_FILENO, STDOUT_FILENO,
			 INT_MAX, SPLICE_F_NONBLOCK);

	       if (len < 0) {
		   if (errno == EAGAIN)
		       continue;
		   perror("tee");
		   exit(EXIT_FAILURE);
	       } else
		   if (len == 0)
		       break;

	       /*
		* Consume stdin by splicing it to a file.
		*/
	       while (len > 0) {
		   slen = splice(STDIN_FILENO, NULL, fd, NULL,
				 len, SPLICE_F_MOVE);
		   if (slen < 0) {
		       perror("splice");
		       break;
		   }
		   len -= slen;
	       }
	   } while (1);

	   close(fd);
	   exit(EXIT_SUCCESS);
       }

SEE ALSO

       splice(2), vmsplice(2), feature_test_macros(7)

COLOPHON

       This page is part of release 3.27 of the Linux man-pages project.  A description of the project, and information about reporting bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.

Linux								    2009-09-15								    TEE(2)

Shell Programming and Scripting