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sed command with -i option failing on Mac, but works on Linux

I've successfully used the following sed command to search/replace text in Linux:

sed -i 's/old_link/new_link/g' *

However, when I try it on my Mac OS X, I get:

"command c expects \ followed by text"

I thought my Mac runs a normal BASH shell. What's up?

EDIT:

According to @High Performance, this is due to Mac sed being of a different (BSD) flavor, so my question would therefore be how do I replicate this command in BSD sed?

EDIT:

Here is an actual example that causes this:

sed -i 's/hello/gbye/g' *
This means that sed sees a "c" in your data as a command. Are you using a variable? Please post something that more closely represents the actual command and some data that you're processing. You can get a simple demonstration of this error by doing echo x | sed c.
@Dennis, the simple command above causes this, though the data it's processing is an entire website (I'm converting all image links), including html and css files...

B
Benjamin W.

If you use the -i option you need to provide an extension for your backups.

If you have:

File1.txt
File2.cfg

The command (note the lack of space between -i and '' and the -e to make it work on new versions of Mac and on GNU):

sed -i'.original' -e 's/old_link/new_link/g' *

Create 2 backup files like:

File1.txt.original
File2.cfg.original

There is no portable way to avoid making backup files because it is impossible to find a mix of sed commands that works on all cases:

sed -i -e ... - does not work on OS X as it creates -e backups

sed -i'' -e ... - does not work on OS X 10.6 but works on 10.9+

sed -i '' -e ... - not working on GNU

Note Given that there isn't a sed command working on all platforms, you can try to use another command to achieve the same result.

E.g., perl -i -pe's/old_link/new_link/g' *


I had the same issue. Thanks for this solution. But where I tried with 'man sed' to find the description of '-i', nothing about using -i '' to ignore backups is there. This is my first blame. Second, when the error "command expects \ followed by text" shows up, why doesn't it directly tell us that it expects a backup name for the option '-i'!!?? Such thing happens everywhere: you get an error but not why the error, then you search for the manual which explains nothing about it. Then you google it to find someone else also has the same problem. I mean, why not giving example in the manual?
@lukmac As far as sed can tell, you DID supply a backup suffix. The backup suffix is s/old_link/new_link/g. The next argument after that is supposed to be the editing commands. Because it interpreted the commands as the backup name, it then took the first filename as the editing commands, but they weren't valid.
Will this always be an issue? Is there some way that Apple might be able to create a workaround / package GNU sed with OSX? Or, couldn't GNU sed support sed -i '' -e ...?
sed -i'' -e seems to not work as expected on mac 10.14
sed -i -- ... seems to work fine. Also mentioned @stackoverflow.com/a/50245014/619961
D
Dennis Williamson

I believe on OS X when you use -i an extension for the backup files is required. Try:

sed -i .bak 's/hello/gbye/g' *

Using GNU sed the extension is optional.


G
Giacomo1968

This works with both GNU and BSD versions of sed:

sed -i'' -e 's/old_link/new_link/g' *

or with backup:

sed -i'.bak' -e 's/old_link/new_link/g' *

Note missing space after -i option! (Necessary for GNU sed)


The first one doesn't work on OSX (I've just tested it on 10.6.8)
For me on OS X (10.10.3), the first one created backup files suffixed with -e. No good. The second one was the only thing that worked for me consistently between Ubuntu and OS X. I didn't want backup files though, so I had to run a rm command right after to delete it.
First line should be rewritten with a space to work on 10.10: sed -i'' ... => sed -i '' ...
@DanielJomphe But adding this space don't work on GNU sed
downvoted since I wasted so much time on this and it didn't work. (the first thing). The backup works but I wanted without, and perl -i -pe from the other answer gave that :)
g
gniourf_gniourf

Had the same problem in Mac and solved it with brew:

brew install gnu-sed

and use as

gsed SED_COMMAND

you can set as well set sed as alias to gsed (if you want):

alias sed=gsed

Why did you give exactly the same answer as Ohad Kravchick?
setting alias like this is not a great idea
Instead of an alias, as recommended in the corresponding brew page, add it to path: PATH="$(brew --prefix)/opt/gnu-sed/libexec/gnubin:$PATH"
Since we're all lazy developers here, add this line to your ~/.zshrc or bashrc file: export PATH="/usr/local/opt/gnu-sed/libexec/gnubin:$PATH" And then run source ~/.zshrc Change to your rc file of choice! Then run which sed to check if it's been changed.
O
Ohad Kravchick

Or, you can install the GNU version of sed in your Mac, called gsed, and use it using the standard Linux syntax.

For that, install gsed using ports (if you don't have it, get it at http://www.macports.org/) by running sudo port install gsed. Then, you can run sed -i 's/old_link/new_link/g' *


.. or if you use homebrew, then install gnu-sed
Thanks @Sudar, double-thumbs up!
H
High Performance Mark

Your Mac does indeed run a BASH shell, but this is more a question of which implementation of sed you are dealing with. On a Mac sed comes from BSD and is subtly different from the sed you might find on a typical Linux box. I suggest you man sed.


Thanks for pointing out the BSD issue- But I'm quite sed illiterate and just need a quick fix for my command- quick glance at man isn't telling me anything
@Yarin -- no, and if I take a quick glance at man sed, that doesn't tell you anything either. Try a longer glance.
Most SO answers are buried somewhere in a man, but that's what SO is for- busy people who need answers from smart people
L
Lucas

Sinetris' answer is right, but I use this with find command to be more specific about what files I want to change. In general this should work (tested on osx /bin/bash):

find . -name "*.smth" -exec sed -i '' 's/text1/text2/g' {} \;

In general when using sed without find in complex projects is less efficient.


-exec is very nice! I'm just wondering if the slash in the end is actually need
@YeLiu: without the \ , the ; got interpreted by the shell when I tried such
a
american-ninja-warrior

Insead of calling sed with sed, I do ./bin/sed

And this is the wrapper script in my ~/project/bin/sed

#!/bin/bash

if [[ "$OSTYPE" == "darwin"* ]]; then
  exec "gsed" "$@"
else
  exec "sed" "$@"
fi

Don't forget to chmod 755 the wrapper script.


assumes you've done brew install gnu-sed beforehand on your Mac
v
v.babak

I've created a function to handle sed difference between MacOS (tested on MacOS 10.12) and other OS:

OS=`uname`
# $(replace_in_file pattern file)
function replace_in_file() {
    if [ "$OS" = 'Darwin' ]; then
        # for MacOS
        sed -i '' -e "$1" "$2"
    else
        # for Linux and Windows
        sed -i'' -e "$1" "$2"
    fi
}

Usage:

$(replace_in_file 's,MASTER_HOST.*,MASTER_HOST='"$MASTER_IP"',' "./mysql/.env")

Where:

, is a delimeter

's,MASTER_HOST.*,MASTER_HOST='"$MASTER_IP"',' is pattern

"./mysql/.env" is path to file


D
Dan Kohn

As the other answers indicate, there is not a way to use sed portably across OS X and Linux without making backup files. So, I instead used this Ruby one-liner to do so:

ruby -pi -e "sub(/ $/, '')" ./config/locales/*.yml

In my case, I needed to call it from a rake task (i.e., inside a Ruby script), so I used this additional level of quoting:

sh %q{ruby -pi -e "sub(/ $/, '')" ./config/locales/*.yml}

k
katopz

Here's how to apply environment variables to template file (no backup need).

1. Create template with {{FOO}} for later replace.

echo "Hello {{FOO}}" > foo.conf.tmpl

2. Replace {{FOO}} with FOO variable and output to new foo.conf file

FOO="world" && sed -e "s/{{FOO}}/$FOO/g" foo.conf.tmpl > foo.conf

Working both macOS 10.12.4 and Ubuntu 14.04.5


I
Igor Dolzhikov

Here is an option in bash scripts:

#!/bin/bash

GO_OS=${GO_OS:-"linux"}

function detect_os {
    # Detect the OS name
    case "$(uname -s)" in
      Darwin)
        host_os=darwin
        ;;
      Linux)
        host_os=linux
        ;;
      *)
        echo "Unsupported host OS. Must be Linux or Mac OS X." >&2
        exit 1
        ;;
    esac

   GO_OS="${host_os}"
}

detect_os

if [ "${GO_OS}" == "darwin" ]; then
    sed -i '' -e ...
else
    sed -i -e ...
fi

can you somehow only condition the gsed presence and use that as a varaible??
@perrohunter A little bit late (only 1 year and an half 😅), but yes it's possible. E.g. if type gsed &> /dev/null; then; echo "use gsed"; else; echo "use sed"; fi;
@Sinetris better late than never hahahaha
a
ashokrajar
sed -ie 's/old_link/new_link/g' *

Works on both BSD & Linux with gnu sed


This creates on linux another filename with e appended
Broken, better to remove it.
It is working on Mac and Linux. What is the issue with this solution?
No, it does not work on Mac BSD Sed - it would create a backupfile with 'e' added to the filename.