&1 " mean?">Answer by Logan Lee for What does " 2>&1 " mean?
You need to understand this in terms of pipe.$ (whoami;ZZZ) 2>&1 | catloganZZZ: command not foundAs you can see both stdout and stderr of LHS of pipe is fed into the RHS (of pipe).This is the...
View Article&1 " mean?">Answer by yuranos for What does " 2>&1 " mean?
Note that 1>&2 cannot be used interchangeably with 2>&1.Imagine your command depends on piping, for example:docker logs 1b3e97c49e39 2>&1 | grep "some log"grepping will happen...
View Article&1 " mean?">Answer by kundan bora for What does " 2>&1 " mean?
I found this very helpful if you are a beginner read thisUpdate:In Linux or Unix System there are two places programs send output to: Standard output (stdout) and Standard Error (stderr).You can...
View Article&1 " mean?">Answer by tim-montague for What does " 2>&1 " mean?
unix_commands 2>&1This is used to print errors to the terminal.When errors are produced, they are written to the "standard error" buffer at memory address &2, and 2 references and streams...
View Article&1 " mean?">Answer by wjordan for What does " 2>&1 " mean?
2>&1 is a POSIX shell construct. Here is a breakdown, token by token:2: "Standard error" output file descriptor.>&: Duplicate an Output File Descriptor operator (a variant of Output...
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&1 " mean?">Answer by Deen John for What does " 2>&1 " mean?
I found this brilliant post on redirection: All about redirectionsRedirect both standard output and standard error to a file$ command &>fileThis one-liner uses the &> operator to redirect...
View Article&1 " mean?">Answer by Matijs for What does " 2>&1 " mean?
Provided that /foo does not exist on your system and /tmp does…$ ls -l /tmp /foowill print the contents of /tmp and print an error message for /foo$ ls -l /tmp /foo > /dev/nullwill send the contents...
View Article&1 " mean?">Answer by ch271828n for What does " 2>&1 " mean?
0 for input, 1 for stdout and 2 for stderr.One Tip:somecmd >1.txt 2>&1 is correct, while somecmd 2>&1 >1.txt is totally wrong with no effect!
View Article&1 " mean?">Answer by ams for What does " 2>&1 " mean?
From a programmer's point of view, it means precisely this:dup2(1, 2);See the man page.Understanding that 2>&1 is a copy also explains why ...command >file 2>&1... is not the same as...
View Article&1 " mean?">Answer by yurenchen for What does " 2>&1 " mean?
Redirecting InputRedirection of input causes the file whose name results from the expansion of word to be opened for reading on file descriptor n, or the standard input (file descriptor 0) if n is not...
View Article&1 " mean?">Answer by Kalanidhi for What does " 2>&1 " mean?
This is just like passing the error to the stdout or the terminal.That is, cmd is not a command:$cmd 2>filenamecat filenamecommand not foundThe error is sent to the file like...
View Article&1 " mean?">Answer by Marcus Thornton for What does " 2>&1 " mean?
2 is the console standard error.1 is the console standard output.This is the standard Unix, and Windows also follows the POSIX.E.g. when you runperl test.pl 2>&1the standard error is redirected...
View Article&1 " mean?">Answer by F. Hauri - Give Up GitHub for What does " 2>&1 " mean?
Some tricks about redirectionSome syntax particularity about this may have important behaviours. There is some little samples about redirections, STDERR, STDOUT, and arguments ordering.1 - Overwriting...
View Article&1 " mean?">Answer by Kurt Pfeifle for What does " 2>&1 " mean?
People, always remember paxdiablo's hint about the current location of the redirection target... It is important.My personal mnemonic for the 2>&1 operator is this:Think of & as meaning...
View Article&1 " mean?">Answer by paxdiablo for What does " 2>&1 " mean?
That construct sends the standard error stream (stderr) to the current location of standard output (stdout) - this currency issue appears to have been neglected by the other answers.You can redirect...
View Article&1 " mean?">Answer by Andrioid for What does " 2>&1 " mean?
To answer your question: It takes any error output (normally sent to stderr) and writes it to standard output (stdout). This is helpful with, for example 'more' when you need paging for all output....
View Article&1 " mean?">Answer by Ayman Hourieh for What does " 2>&1 " mean?
File descriptor 1 is the standard output (stdout).File descriptor 2 is the standard error (stderr).At first, 2>1 may look like a good way to redirect stderr to stdout. However, it will actually be...
View Article&1 " mean?">Answer by dbr for What does " 2>&1 " mean?
To redirect stdout to file.txt:echo test > file.txtThis is equivalent to:echo test 1> file.txtTo redirect stderr to file.txt:echo test 2> file.txtSo >& is the syntax to redirect a...
View Article&1 " mean?">Answer by Colin Burnett for What does " 2>&1 " mean?
The numbers refer to the file descriptors (fd). Zero is stdinOne is stdoutTwo is stderr2>&1 redirects fd 2 to 1. This works for any number of file descriptors if the program uses them.You can...
View Article&1 " mean?">What does " 2>&1 " mean?
To combine stderr and stdout into the stdout stream, we append this to a command:2>&1e.g. to see the first few errors from compiling g++ main.cpp:g++ main.cpp 2>&1 | headWhat does...
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