Combine Standard Error And Standard Output
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Redirect Standard Error To Standard Output
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Standard Output And Standard Error In Unix
Join them; it only takes a 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. combine standard deviation How do I do that in Bash? bash 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 64.4k145334456 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 linux pipe standard error 9:17 dirkgently 74.2k1293162 6 Somebody should restore to the second edit 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 41.6k13103187 answered Mar 12 '09 at 9:16 Mark
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Combine Stdout And Stderr
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Bash Redirect Stdout And Stderr To Dev Null
Badges Ask Question x Dismiss Join 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 http://stackoverflow.com/questions/637827/redirect-stderr-and-stdout-in-a-bash-script minute: Sign up How can I redirect and append both stdout and stderr to a file with Bash? up vote 729 down vote favorite 191 To redirect stdout to a truncated file in Bash, I know to use: cmd > file.txt To redirect stdout in Bash, appending to a file, I know to use: cmd >> file.txt To redirect both stdout http://stackoverflow.com/questions/876239/how-can-i-redirect-and-append-both-stdout-and-stderr-to-a-file-with-bash and stderr to a truncated file, I know to use: cmd &> file.txt How do I redirect both stdout and stderr appending to a file? cmd &>> file.txt did not work for me. linux bash redirect stream pipe share|improve this question edited Dec 17 '15 at 16:27 Jahid 8,52742348 asked May 18 '09 at 4:19 flybywire 64.4k145334456 16 I would like to note that &>outfile is a Bash (and others) specific code and not portable. The way to go portable (similar to the appending answers) always was and still is >outfile 2>&1 –TheBonsai May 18 '09 at 4:48 add a comment| 6 Answers 6 active oldest votes up vote 929 down vote accepted cmd >>file.txt 2>&1 share|improve this answer answered May 18 '09 at 4:23 Alex Martelli 476k878651146 20 works great! but is there a way to make sense of this or should I treat this like an atomic bash construct? –flybywire May 18 '09 at 8:15 135 It's simple redirection, redirection statements are evaluated, as always, from left to right. >>file : Red. STDOUT to file (append mode) (s
Support Search GitHub This repository Watch 526 Star 15,117 Fork 1,207 Unitech/pm2 Code Issues 436 Pull requests 31 Projects 1 Wiki Pulse Graphs New issue How can I combine the output and error logs? #337 Closed dandv opened this Issue https://github.com/Unitech/pm2/issues/337 Mar 7, 2014 · 8 comments Projects None yet Labels None yet Milestone No milestone Assignees No one assigned 4 participants dandv commented Mar 7, 2014 forever has a -l option that directs both STDOUT and STDERR of the http://rc3.org/2009/05/08/merging-stdout-and-stderr/ app into the same file. This is useful as I can see after which operations (output via console.log) some error has occurred (output via console.error). How can I do this with pm2? Collaborator soyuka commented Mar 7, 2014 I standard error don't think it's a good idea but perhaps that setting the same output file into a JSON declaration would work ;). dandv commented Mar 7, 2014 I tried passing the same output file to -o and -e, but pm2 logs was confused by that. Every STDOUT line was shown both as "out" and as "err". Unitech referenced this issue Apr 4, 2014 Closed Roadmap to 0.8.x #376 10 of 10 tasks complete Owner Unitech commented Apr 14, 2014 standard error and You can now merge all logs of the same process name to the same output and error file via the option --merge-logs Unitech closed this Apr 14, 2014 dandv commented Apr 15, 2014 Let's say I only have one process. Can --merge-logs interleave the -e (error) and -o (output) logs into one file? This would assist in seeing what has happened before an error occurred, because the error message itself in a separate file will be out of context. dandv referenced this issue Apr 15, 2014 Closed Document the --merge-logs option in the README #398 dandv commented Apr 17, 2014 Could we maybe reopen this issue? As I see, --merge-logs combines logs from instanced, but not STDOUT and STDERR. Here's a workaround I found, until pm2 enables support for this. It's a bit more complicated because of the numbers added to the end of the log filenames. MYLOG_BASENAME="myapp.log" pm2 start myapp.js -o $MYLOG_BASENAME.out -e $MYLOG_BASENAME.err ACTUAL_LOG=$(pm2 -m l | grep -o /.\*$MYLOG_BASENAME.\*out) ACTUAL_ERR=$(pm2 -m l | grep -o /.\*$MYLOG_BASENAME.\*err) tail -f $ACTUAL_LOG $ACTUAL_ERR | tee -a $MYLOG_BASENAME.both Please let me know if there's a simpler way to achieve this. dandv commented May 29, 2014 Any updates? The workaround above require running tail all the time, in parallel with the app. Cumbersome. liukun commented Mar 3, 2016 Seems no good options here. My best bet is to use Heka or Logstash listening on T
standard error. The two are separated so that if you're redirecting the output of the command to a file or piping it to another command, error messages generated by the command aren't included with the expected output of the command. This becomes a problem when you want to capture STDERR in a file, or pipe it to a command like grep so that you can search for specific things in the errors. Fortunately, there's a way to do this: $ my_command 2>&1 | grep "somestring" The magic here is 2>&1. It means, "Redirect stream 2 to stream 1." In Bourne shell derivatives (like bash, zsh, and ksh), stream 2 is STDERR and stream 1 is STDOUT. Once the streams are merged, you can do whatever you want with the single output stream, like pipe it to grep or redirect it to a file. One common construct you'll see in cron jobs is this: 1 0 * * * run_some_script.sh > /dev/null 2>&1 Cron helpfully sends an email to the user that owns the cron job whenever the command cron is running produces any output. Putting the merged redirect to /dev/null in there sends both STDERR and STDOUT to the bit bucket so that no email is generated. Of course that also means that cron is eating the error messages, so if something goes wrong you won't be notified in the traditional way. Commentary shellunixYLSNED Previous post The future of syndication Next post Judging restaurants by a single dish 3 Comments Jacob Davies May 8, 2009 at 4:57 pm You can get around that to some extent by making your cron'd jobs send you email if something really bad happens. You just have to remember to actually do that, and not to just output to stderr under the assumption that someone will read it. It's tricky because a lot of programs generate stderr output under normal operating conditions. I think that is a mistake, but it's a mistake well-ingrained by now. daveadams May 8, 2009 at 6:03 pm I've come up with a cron wrapper script that captures stdout and stderr to a log file that I can check if I need to (rotated daily and cleaned up after a set period of time). The wrapper handles timestamping, etc, so I can just have our cron scripts "log" to stdout. The best part is then that if the script exits non-zero, it sends an email to me and the other systems folks, and for real emergency situations, an exit code of 255 will page us. The script is really simple, and we've moved nearly all of our crons to