Does Standard Error To File
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Redirect Standard Error To File Windows
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What Does Standard Error Mean
them; it only takes a minute: Sign up Here's how it works: Anybody can ask a question Anybody can answer The best answers are voted up and rise to the top How to redirect stderr to a file up vote 7 down vote favorite 1 While using nohup to put a command to run in background what does standard error mean in regression some of content appear in terminal. cp: error reading ‘/mnt/tt/file.txt’: Input/output error cp: failed to extend ‘/mnt/tt/file.txt’: Input/output error I want to save that content to a file. command-line redirect share|improve this question edited May 18 '15 at 13:42 asked May 18 '15 at 12:31 André M. Faria 3861618 add a comment| 1 Answer 1 active oldest votes up vote 12 down vote accepted There are two main output streams in Linux (and other OSs), standard output (stdout)and standard error (stderr). Error messages, like the ones you show, are printed to standard error. The classic redirection operator (command > file) only redirects standard output, so standard error is still shown on the terminal. To redirect stderr as well, you have a few choices: Redirect stderr to another file: command > out 2>error Redirect stderr to stdout (&1), and then redirect stdout to a file: command >out 2>&1 Redirect both to a file: command &> out For more information on the various control and redirection operators, see
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What Does Standard Error Mean In Linear Regression
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the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just like you, helping each other. Join them; it only takes a what does standard error mean in regression analysis minute: Sign up Redirect stderr and stdout in a Bash script up vote 365 down vote favorite 118 I want to redirect both stdout and stderr of a process to a single file. How do I do that in Bash? bash http://askubuntu.com/questions/625224/how-to-redirect-stderr-to-a-file shell redirect pipe share|improve this question edited Nov 2 '15 at 12:01 Peter Mortensen 10.2k1369107 asked Mar 12 '09 at 9:14 flybywire 64.5k145334456 add a comment| 9 Answers 9 active oldest votes up vote 419 down vote accepted Take a look here. Should be: yourcommand &>filename (redirects both stdout and stderr to filename). share|improve this answer edited Oct 7 '10 at 5:44 David Johnstone 14k115568 answered Mar 12 '09 at 9:17 dirkgently 74.2k1293162 6 Somebody should restore to the second edit http://stackoverflow.com/questions/637827/redirect-stderr-and-stdout-in-a-bash-script of this comment. Supplementary info to the question shouldn't be removed, especially in a 6 month old answer. –Jeff Ferland Sep 1 '09 at 14:14 13 This syntax is deprecated according to the Bash Hackers Wiki. Is it? –Salman Abbas Jul 11 '12 at 1:10 7 According to wiki.bash-hackers.org/scripting/obsolete, it seems to be obsolete in the sense that it is not part of POSIX, but the bash man page makes no mention of it being removed from bash in the near future. The man page does specify a preference for '&>' over '>&', which is otherwise equivalent. –chepner Jul 16 '12 at 20:45 6 I guess we should not use &> as it is not in POSIX, and common shells such as "dash" do not support it. –Sam Watkins Apr 23 '13 at 8:24 11 An extra hint: If you use this in a script, make sure it starts with #!/bin/bash rather than #!/bin/sh, since in requires bash. –Tor Klingberg Oct 1 '13 at 17:47 | show 7 more comments up vote 261 down vote do_something 2>&1 | tee -a some_file This is going to redirect stderr to stdout and stdout to some_file and print it to stdout. share|improve this answer edited Oct 27 '15 at 10:33 rubenvb 41.6k13103188 answered Mar 12 '09 at 9:16 Marko 17.9k125999 3 I was searching SO for how to do this with pipe and tee. You da man! –Ogre Psalm33 Aug 4 '
How to get Help for Perl? Perl on the command line Core Perl documentation and CPAN module documentation POD - Plain Old Documentation Debugging Perl scripts Scalars Common Warnings and http://perlmaven.com/stdout-stderr-and-redirection Error messages in Perl Automatic string to number conversion or casting in Perl Conditional statements, using if, else, elsif in Perl Boolean values in Perl Numerical operators String operators: concatenation (.), repetition (x) undef, http://www.linfo.org/standard_error.html the initial value and the defined function of Perl Strings in Perl: quoted, interpolated and escaped Here documents, or how to create multi-line strings in Perl Scalar variables Comparing scalars in Perl String standard error functions: length, lc, uc, index, substr Number Guessing game while loop Scope of variables in Perl Short-circuit in boolean expressions Files How to exit from a Perl script? Standard output, standard error and command line redirection Warning when something goes wrong What does die do? Writing to files with Perl Appending to files Open and read from text files Don't Open Files in the old way does standard error slurp mode - reading a file in one step Lists and Arrays Perl for loop explained with examples Perl Arrays Processing command line arguments - @ARGV in Perl How to process command line arguments in Perl using Getopt::Long Advanced usage of Getopt::Long for accepting command line arguments Perl split - to cut up a string into pieces How to read a CSV file using Perl? join The year of 19100 Scalar and List context in Perl, the size of an array Reading from a file in scalar and list context STDIN in scalar and list context Sorting arrays in Perl Sorting mixed strings Unique values in an array in Perl Manipulating Perl arrays: shift, unshift, push, pop Reverse Polish Calculator in Perl using a stack Reverse an array, a string or a number The ternary operator in Perl qw - quote word Subroutines Subroutines and functions in Perl Variable number of parameters in Perl subroutines Understanding recursive subroutines - traversing a directory tree Hashes, arrays Hashes in Perl Creating a hash from an array in Perl Perl hash in scalar and list context How to sort a hash in Perl? Count the frequency of words in text usi
standard streams of data. Each process is automatically initialized with (i.e., assigned) three data streams: one input stream, called standard input, and two output streams, called standard output and standard error. These streams consist of data in plain text (i.e., human readable characters) and are considered to be special types of files. A process is an instance of an executing program. Standard output, sometimes abbreviated stdout, refers to the destination of the output from command line programs exclusive of error messages, and it is the display screen by default. Standard input is the source of input data for a command line program, and by default it is any text entered from the keyboard. A command is an instruction telling a computer to do something, such as run a program. As is the case with standard output, standard error is also the display screen by default, and it can likewise be redirected (i.e., sent to a destination other than its default destination) to a file, printer, another program, etc. The reason that standard error is a separate data stream from standard output is so that the two streams to be redirected separately and thereby prevent them from becoming intermingled. As an example of an error message, the cat command, among whose functions is to read the contents of files, will produce an error message if an attempt is made to use it to read a non-existent file, such as a file named nofile, i.e., cat nofile In this case, an error message similar to the following will appear on a new line on the monitor screen (because the standard error was not redirected): cat: nofile: No such file or directory . Standard error can be redirected with the standard error redirection operator, which is designated by the numeral 2 followed directly (i.e., with no intervening space) by a rightward pointing angular bracket (i.e., 2>). This operator will create the file to which standard error is redirected if a file with that name does not yet exist, or it will overwrite the contents of the file if a file with the same name already exists. For instance, the standard error from the above example could be redirected from appearing on the display screen to being written to a file named file1 as follows: cat nofile 2> file1 An alternative is to use the standard error appending operator, designated by the numeral 2 followed by two rightward pointing angular brac