2
votes
2answers
51 views

Decoding “prog > file 2>&1”

I am having some difficulty understanding the construct prog > file 2>&1. I have read that it means "Send stdout and stderr to file". But my question is how? I understand that prog > ...
4
votes
2answers
62 views

How to redirect stdout to a file and read from the same file simultaneously with another task?

I want to run a task (which takes quite a long time) remotely in Ubuntu Linux Bash via nohup and redirect stdout to a file, e.g.: nohup task > out.txt & From time to time I would like to ...
9
votes
3answers
465 views

tee stdout to stderr?

I'd like to send stdout from one process to the stdin of another process, but also to the console. Sending stdout to stdout+stderr, for instance. For example, I've got git edit aliased to the ...
1
vote
1answer
411 views

Linux : how to redirect stdout & stderr to logger?

I have a program I need to run at startup, it has output on stdout and stderr that I want to redirect to the system log using the logger command. What I have in my startup script is thie: ...
4
votes
1answer
103 views

Can redirecting stdout and stderr to the same file mangle lines?

I've read that when redirecting stdout and stderr to the same file using 2>&1, stdout is usually block buffered while stderr is unbuffered. If a very long line is written to stdout, requiring ...
3
votes
2answers
195 views

Bash if script is called from terminal echo stdout to terminal, if from cron do not echo output

I would like to have a service watchdog script echo the status to the screen if called like ./watchdog.sh but if it is run by cron, there is no need to echo output. What is the proper method? Where ...
2
votes
3answers
107 views

How can a command have more than one output?

In this answer, at the very bottom, Gilles mentions that a command can have more than one output or input. Yes, there's cat foo bar | something, for having both foo and bar as inputs, and there's tee ...
1
vote
1answer
100 views

Pipe not picking up stdout

I am running a java program from a OS X 10.8 bash terminal, and are trying to rederect the output it is producing. However, when either running this throug a pipe, or rederecting it to a file, the ...
5
votes
1answer
68 views

Is it possible to create sticky redirection from stdout/stderr

Consider such code: echo hello >> log.txt echo world >> log.txt I execute command with stdout redirection. Is it possible to create sticky redirection? Something like this: redir ...
0
votes
2answers
459 views

Redirecting stdin with stdout to file

So I have a program that takes in user input and outputs text based on the input. EDIT2: I want to create a script that runs a C executable and the script feeds the C program input from a file and ...
2
votes
2answers
71 views

redirecting std output and std error

I have been trying to figure out the relationship between file descriptors. One thing I don't understand is, how is: ls -l /bin/usr > ls-output.txt 2>&1 different from: ls -l /bin/usr ...
1
vote
2answers
3k views

How can I get vsftpd version into shell variable?

I want to get vsftpd version into shell variable. I can get it to console with ease: # vsftpd -version vsftpd: version 2.2.2 Also I can get a lot of other info into variable: # i=`bash --version ...
1
vote
2answers
301 views

Redirecting tr stdout to a file [duplicate]

Possible Duplicate: How can I make iconv replace the input file with the converted output? Can I read and write to the same file in Linux without overwriting it? $ cat test.txt This is a ...
13
votes
2answers
670 views

Redirect stderr from an already running script

I've been running a script for several days now. I redirected stdout to $HOME/mylog, but didn't redirect stderr since I thought there would be nothing on it. Suddenly thousands of lines started coming ...
5
votes
1answer
588 views

Append output to a file and redirect stderr to null

How can I append the result of a command to a file and redirect stderr to null?
5
votes
2answers
564 views

Wrapping a shell script with tee

There is a bash script which prints some logs and allows some arguments. The script prints the logs to STDOUT. Let's say the script's name is AAA.sh I'd also like to make the script to print the logs ...
3
votes
1answer
400 views

Redirecting/grep'ing an existing shell's STDOUT

I run a lot of long running processes (simulations) that print progress to STDOUT. I occasionally forget to redirect to STDOUT to a file I can grep, and it's usually too far along to restart. ...
3
votes
1answer
318 views

Shell script doesn't paint last line of stdout to screen without user input

I have a shell script that's happily doing all my backup process and writing progress to stderr and stdout, with one exception — the last line doesn't get written to my terminal (if I call the script ...
6
votes
2answers
3k views

what is meant by connecting STDOUT and STDIN?

This is a newbie question. I'm reading a book, it says: Every process has at least three communication channels available to it: “standard input” (STDIN), “standard output” (STDOUT), and ...
7
votes
3answers
5k views

bash: Use a variable to store stderr|stdout redirection

Is there any way to redirect stdout and stderr via variable like adding command options in script? For example I have a script: #!/bin/bash -x TEST=">/dev/null 2>&1" OPT='-p -v' mkdir $OPT ...