Is there a way to make bash display stderr messages in red color?

  • 4
    I guess bash will never colorize its output: some program may want to parse something, and colorizing will spoil data with escaped sequences. A GUI app should handle colors, i guess.
    – kolypto
    Aug 26, 2009 at 22:20
  • Combining Balázs Pozsár and killdash9 answer gives the crisp: function color { "$@" 2> >(sed $'s,.*,\e[31m&\e[m,') } Works for bash and zsh. Can't add this as an answer b/c reputation. Sep 14, 2018 at 19:38
  • 2
    I am waiting for an answer that modifies bash to do this. The solutions below all actually modify stderr and possibly even reorder it w.r.t. stdout which breaks things when the exact byte sequence of stderr must be preserved e.g. when piping.
    – masterxilo
    Sep 21, 2018 at 9:06
  • 1
    The downside to these solutions is that they work line-by-line, i.e. they buffer the input until a NL is encountered. While that might be okay in most cases, it disables e.g. various progress bars which rely on CR and flushing of output. Dec 1, 2020 at 10:37

11 Answers 11

command 2> >(while read line; do echo -e "\e[01;31m$line\e[0m" >&2; done)
  • 11
    Great! But i wonder if there's a way to make it permanent :)
    – kolypto
    Aug 26, 2009 at 21:47
  • 10
    Great tip! Suggestion: By adding >&2 right before ; done), the output intended for stderr actually is written to stderr. That's helpful if you want to capture the normal output of the program.
    – henko
    Oct 31, 2012 at 8:12
  • 8
    The following uses tput, and is slightly more readable in my opinion: command 2> >(while read line; do echo -e "$(tput setaf 1)$line$(tput sgr0)" >&2; done) Feb 14, 2013 at 21:59
  • 3
    I think executing 2 tput processes for each output line is not elegant at all. Maybe if you would store the output of the tput commands in a variable and use those for each echo. But then again, readability is not really better. Oct 7, 2014 at 12:09
  • 2
    This solution does not preserve whitespace but I like it for its brevity. IFS= read -r line should help but doesn't. Not sure why.
    – Max Murphy
    Jul 1, 2016 at 11:05

Method 1: Use process substitution directly:

command 2> >(sed $'s,.*,\e[31m&\e[m,'>&2)

Method 2: Create a function in bash or zsh :

color()(set -o pipefail;"$@" 2> >(sed $'s,.*,\e[31m&\e[m,'>&2))
export -f color

Use it like this:

$ color command

Both methods will show the command's stderr in red.

Keep reading for an explanation of how it works. There are some interesting features demonstrated by these commands. The first 3 bullet points only apply to Method 2. The rest apply to both methods.

  • color()... — Creates a bash function called color.
  • set -o pipefail — This is a shell option that preserves the error return code of a command whose output is piped into another command. This is done in a subshell, which is created by the parentheses, so as not to change the pipefail option in the outer shell.
  • "$@" — Executes the arguments to the function as a new command. "$@" is equivalent to "$1" "$2" ...
  • 2> >(...) — The >(...) syntax is called process substitution. Preceded by 2> , it connects the stderr of the main command to the stdin of the sed process inside the parentheses.
  • sed ... — Because of the redirects above, sed's stdin is the stderr of the executed command. Its function is to surround each line with color codes.
  • $'...' A bash construct that causes it to understand backslash-escaped characters
  • .* — Matches the entire line.
  • \e[31m — The ANSI escape sequence that causes the following characters to be red
  • & — The sed replace character that expands to the entire matched string (the entire line in this case).
  • \e[m — The ANSI escape sequence that resets the color.
  • >&2 — Shorthand for 1>&2, this redirects sed's stdout to stderr.
  • 5
    Great answer and even better explanation Oct 22, 2014 at 19:56
  • 1
    Is there a way to make it work in zsh?
    – Eyal Levin
    Aug 25, 2016 at 9:14
  • 2
    ZSH doesn't recognize the shorthand redirection forms. It just needs two more 1's, i.e. : zsh: color()(set -o pipefail;"$@" 2>&1 1>&3|sed $'s,.*,\e[31m&\e[m,'1>&2)3>&1
    – Rekin
    Aug 2, 2018 at 10:12
  • 1
    The first solution has a bit of a problem in that the pipeline doesn't wait for the output to complete before exiting, so sometimes the colored output will happen after the next prompt, or, if the calling shell exits at that point, it might not happen at all. To demonstrate that consistently, put a sleep 1; before the sed.
    – Don Hatch
    Dec 25, 2019 at 5:24
  • 2
    This won't preserve order of execution.
    – Jonah
    Apr 11, 2020 at 13:55

You can also check out stderred: https://github.com/sickill/stderred

  • Wow, this utility is great, the only thing that it would need is to have an apt repository that installs it for all users, with one line, not having to do more work to enable it.
    – sorin
    Apr 3, 2012 at 14:17
  • Seemed to work well when I tested it with a build script in a separate terminal, but I'm hesitant to use it globally (in .bashrc). Thanks though!
    – Joel Purra
    Aug 24, 2012 at 15:18
  • 2
    In OS X El Capitan, the way this works (DYLD_INSERT_LIBRARIES) is "broken" in system binaries because they are protected by SIP. So it might be better to use the bash options given in other answers.
    – hmijail
    Apr 22, 2016 at 21:41
  • 1
    @hmijail for MacOS please follow github.com/sickill/stderred/issues/60 so we can find a workaround, a partial one already exists but is a little bit buggy.
    – sorin
    Jul 16, 2018 at 7:57
  • 2
    This is really ingenious. And it's the only answer I've seen that doesn't scramble the order of stdout and stderr (all shell-based solutions do, as far as I can see).
    – Don Hatch
    Dec 25, 2019 at 5:29

The bash way of making stderr permanently red is using 'exec' to redirect streams. Add the following to your bashrc:

exec 9>&2
exec 8> >(
    while IFS='' read -r line || [ -n "$line" ]; do
       echo -e "\033[31m${line}\033[0m"
function undirect(){ exec 2>&9; }
function redirect(){ exec 2>&8; }
trap "redirect;" DEBUG

I have posted on this previously: How to set font color for STDOUT and STDERR

  • related: unix.stackexchange.com/questions/367636/…
    – phil294
    May 29, 2017 at 3:59
  • 1
    This is the best answer by far; easy to implement without installation/requiring sudo privilege, and can be generalized to all commands.
    – Luke Davis
    Sep 26, 2017 at 2:25
  • 1
    Unfortunately this doesn't play well with command chaining (command && nextCommand || errorHandlerCommand). The error output goes after errorHandlerCommand output. Jun 18, 2018 at 23:30
  • 1
    Similarly, if I source ~/.bashrc twice with this, my terminal basically locks up.
    – Dolph
    Sep 11, 2018 at 20:11
  • 1
    Not a viable solution for me: (i) I cannot $sudo su in terminal any longer, (ii) it colours red non stderr streams e.g. $read "Press Enter", (iii) it disrupts the order of stderr and stdout mingling up messages out of order.
    – afora377
    May 8, 2022 at 1:06



I've made a wrapper script that implements Balázs Pozsár's answer in pure bash. Save it in your $PATH and prefix commands to colorize their output.


    if [ $1 == "--help" ] ; then
        echo "Executes a command and colorizes all errors occured"
        echo "Example: `basename ${0}` wget ..."
        echo "(c) o_O Tync, ICQ# 1227-700, Enjoy!"
        exit 0

    # Temp file to catch all errors

    # Execute command
    "$@" 2> >(while read line; do echo -e "\e[01;31m$line\e[0m" | tee --append $TMP_ERRS; done)

    # Display all errors again
    if [ -s "$TMP_ERRS" ] ; then
        echo -e "\n\n\n\e[01;31m === ERRORS === \e[0m"
        cat $TMP_ERRS
    rm -f $TMP_ERRS

    # Finish
    exit $EXIT_CODE

  • 2
    This could be made more efficient if "|tee..." was put after "done".
    – Juliano
    Aug 27, 2009 at 1:27

You can use a function like this


color() {
      printf '\033[%sm%s\033[m\n' "$@"
      # usage color "31;5" "string"
      # 0 default
      # 5 blink, 1 strong, 4 underlined
      # fg: 31 red,  32 green, 33 yellow, 34 blue, 35 purple, 36 cyan, 37 white
      # bg: 40 black, 41 red, 44 blue, 45 purple
string="Hello world!"
color '31;1' "$string" >&2

I append >&2 to print to stderr

  • 4
    Not addressing the problem. You haven't provided a way of separating stderr from stdout, which is what the O.P. is interested in. Aug 27, 2009 at 1:54

I have a slightly modified version of O_o Tync's script. I needed to make these mods for OS X Lion and it's not perfect because the script sometimes completes before the wrapped command does. I've added a sleep but I'm sure there's a better way.


   if [ $1 == "--help" ] ; then
       echo "Executes a command and colorizes all errors occured"
       echo "Example: `basename ${0}` wget ..."
       echo "(c) o_O Tync, ICQ# 1227-700, Enjoy!"
       exit 0

   # Temp file to catch all errors
   TMP_ERRS=`mktemp /tmp/temperr.XXXXXX` || exit 1

   # Execute command
   "$@" 2> >(while read line; do echo -e "$(tput setaf 1)$line\n" | tee -a $TMP_ERRS; done)

   sleep 1
   # Display all errors again
   if [ -s "$TMP_ERRS" ] ; then
       echo -e "\n\n\n$(tput setaf 1) === ERRORS === "
       cat $TMP_ERRS
       echo "No errors collected in $TMP_ERRS"
   rm -f $TMP_ERRS

   # Finish
   exit $EXIT_CODE

This solution worked for me: https://superuser.com/questions/28869/immediately-tell-which-output-was-sent-to-stderr

I've put this function in my .bashrc or .zshrc:

# rse <command string>
function rse()
    # We need to wrap each phrase of the command in quotes to preserve arguments that contain whitespace
    # Execute the command, swap STDOUT and STDERR, colour STDOUT, swap back
    ((eval $(for phrase in "$@"; do echo -n "'$phrase' "; done)) 3>&1 1>&2 2>&3 | sed -e "s/^\(.*\)$/$(echo -en \\033)[31;1m\1$(echo -en \\033)[0m/") 3>&1 1>&2 2>&3

Then for example:

$ rse cat non_existing_file.txt

will give me a red output.

  • You can add set -o pipefail; before (eval for redirect exit code
    – kvaps
    Jun 27, 2019 at 14:34
  • also add the " to eval to preserve spaces in the arguments
    – kvaps
    Jun 27, 2019 at 14:42

using xargs and printf:

command 2> >(xargs -0 printf "\e[31m%s\e[m" >&2)

a version using fifos

mkfifo errs
stdbuf -o0 -e0 -i0 grep . foo | while read line; do echo -e "\e[01;31m$line  \e[0m" >&2; done &
stdbuf -o0 -e0 -i0 sh $script 2>errs

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