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

Galore builders trust connected the sed bid for its almighty matter manipulation capabilities. Its successful-spot modifying characteristic, activated with the -i action, is particularly utile for streamlining scripting duties. Nevertheless, a communal component of vexation arises once utilizing sed -i connected macOS, wherever it behaves otherwise than connected Linux. This discrepancy frequently leads to sudden errors and wasted clip debugging scripts that relation absolutely good connected Linux programs. This station delves into the causes down this incompatibility and provides effectual options for reaching accordant sed behaviour crossed antithetic working methods.

Knowing the `sed -i` Discrepancy

The center quality lies successful however macOS and Linux grip successful-spot record enhancing with sed. Connected Linux, sed -i straight modifies the first record. macOS, primarily based connected BSD, requires an statement pursuing the -i emblem, which specifies the backup record delay. If nary delay is supplied, sed connected macOS creates a fresh record with the aforesaid sanction, efficaciously overwriting the first with out creating a backup. This tin pb to information failure if not dealt with cautiously.

This quality stems from the underlying sed implementations connected all working scheme – GNU sed connected Linux and BSD sed connected macOS. This seemingly insignificant quality tin origin important complications once porting scripts betwixt these techniques.

For case, a book utilizing sed -i 's/aged/fresh/g' record.txt would activity flawlessly connected Linux, modifying record.txt straight. Connected macOS, the aforesaid bid would erase the first contented of record.txt and regenerate it with the modified matter with out creating a backup. This tin beryllium disastrous if you’re not anticipating this behaviour.

Options for Transverse-Level Compatibility

Respective methods tin guarantee your sed scripts activity constantly crossed macOS and Linux. 1 attack is to ever supply a backup delay, equal if it’s an bare drawstring. The bid sed -i '' 's/aged/fresh/g' record.txt volition activity connected some programs. Connected macOS, it creates a backup with nary delay (basically the first record is deleted last creating the fresh 1), mimicking the behaviour of GNU sed.

Different resolution is to usage a conditional message successful your book to observe the working scheme and set the sed bid accordingly. This attack supplies higher flexibility and power however provides complexity to the book.

Eventually, see utilizing a transverse-level scripting communication similar Python oregon Perl, which frequently person constructed-successful capabilities for record manipulation that summary distant these working scheme variations. This mightiness beryllium a much sturdy resolution for analyzable scripts wherever portability is a capital interest.

Champion Practices for Utilizing `sed -i`

Careless of the working scheme, warning is ever suggested once utilizing sed -i. Creating backups is a important condition nett, peculiarly once running with crucial information. Ever trial your sed instructions connected a transcript of your information earlier making use of them to the first record.

Different champion pattern is to brand your scripts arsenic express arsenic imaginable. Utilizing a backup delay intelligibly signifies the meant behaviour, lowering the hazard of unintentional information failure. This besides improves book readability and maintainability.

Daily expressions are a almighty portion of sed, however they tin besides beryllium analyzable and mistake-susceptible. Usage instruments similar regex101.com to trial and debug your daily expressions earlier incorporating them into your sed instructions.

Alternate Instruments for Matter Manipulation

Piece sed is a invaluable implement, respective options message akin performance with possibly improved transverse-level compatibility. awk, for illustration, is different almighty matter processing inferior that tin execute galore of the aforesaid duties arsenic sed.

Much contemporary scripting languages similar Python and Perl message almighty drawstring manipulation capabilities and constructed-successful capabilities for record dealing with. These languages frequently supply better flexibility and transverse-level compatibility than sed.

Selecting the correct implement relies upon connected the circumstantial project and your comfortableness flat with antithetic languages. For elemental matter substitutions and transformations, sed stays a almighty and businesslike action. For much analyzable operations oregon enhanced transverse-level compatibility, exploring alternate instruments mightiness beryllium worthwhile.

Ever usage a backup delay with sed -i, equal if it’s bare.
Trial your sed instructions totally earlier making use of them to captious information.

Make a transcript of your information.
Trial your sed bid connected the transcript.
If the outcomes are arsenic anticipated, use the bid to the first information.

Larn Much Astir Ammunition ScriptingFeatured Snippet: To guarantee your sed -i instructions activity seamlessly crossed macOS and Linux, ever see a backup delay, equal an bare 1 (e.g., sed -i '' 's/aged/fresh/g' record.txt). This prevents unintentional information failure connected macOS piece sustaining compatibility with Linux.

GNU Sed Guide

FreeBSD Sed Handbook

Sed Questions connected Stack Overflow

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Often Requested Questions

Q: Wherefore does sed -i behave otherwise connected macOS and Linux?
A: The quality stems from the antithetic sed implementations: GNU sed connected Linux and BSD sed connected macOS. GNU sed straight modifies the record, piece BSD sed requires a backup delay.

Knowing the nuances of sed -i crossed antithetic working programs is important for penning sturdy and moveable scripts. By adopting the methods and champion practices outlined successful this article, you tin debar communal pitfalls and guarantee your matter manipulation duties execute reliably connected some macOS and Linux. Commencement implementing these methods present for a smoother and much businesslike scripting education. Research associated matters similar ammunition scripting champion practices and daily look optimization to additional heighten your abilities.

Question & Answer :
I’ve efficiently utilized the pursuing sed bid to hunt/regenerate matter successful Linux:

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

Nevertheless, once I attempt it connected my Mac OS X, I acquire:

“bid c expects \ adopted by matter”

I idea my Mac runs a average BASH ammunition. What’s ahead?

EDIT:

In accordance to @Advanced Show, this is owed to Mac sed being of a antithetic (BSD) spirit, truthful my motion would so beryllium however bash I replicate this bid successful BSD sed?

EDIT:

Present is an existent illustration that causes this:

sed -i 's/hullo/gbye/g' *

Moveable resolution beneath

Wherefore you acquire the mistake

The -i action (alternatively, --successful-spot) means that you privation information edited successful-spot, instead than streaming the alteration to a fresh spot.

Modifying a record successful-spot suggests a demand for a backup record - and truthful a person-specified delay is anticipated last -i, however the parsing of the delay statement is dealt with otherwise nether GNU sed & Mac (BSD) sed:

GNU : “If nary delay is provided, the first record is overwritten with out making a backup.” - efficaciously, you tin omit specify a record delay altogether. The delay essential beryllium provided instantly last the -i, with nary intervening abstraction.
Mac (BSD) : “If a zero-dimension delay is fixed, nary backup volition beryllium saved.” - you essential provision an delay, however it tin beryllium the bare drawstring ’’ if you privation, to disable the backup.

Truthful GNU & Mac volition construe this otherwise:

sed -i 's/hullo/bye/g' just_a_file.txt

GNU : Nary delay is provided instantly last the -i, truthful make nary backup, usage s/hullo/bye/g arsenic the matter-enhancing bid, and enactment connected the record just_a_file.txt successful-spot.
Mac (BSD) : Usage s/hullo/bye/g arsenic the backup record delay (!) and just_a_file.txt arsenic the enhancing bid (daily look).
Consequence: the bid codification utilized is j (not a legitimate bid codification for substitution, e.g. s), therefore we acquire the mistake invalid bid codification j.

# This inactive make a `my_file.txt-e` backup connected macOS Sonoma (14.5) # and a `my_file.txt''` connected Linux sed -i'' -e 's/hullo/bye/g' my_file.txt

Putting the delay instantly last the -i (eg -i'' oregon -i'.bak', with out a abstraction) is what GNU sed expects, however macOS anticipate a abstraction last -i (eg -i '' oregon -i '.bak').

~~and is present accepted by Mac (BSD) sed excessively, although it wasn’t tolerated by earlier variations (eg with Mac OS X v10.6, a abstraction was required last -i, eg -i '.bak').~~

The -e parameter permits america to beryllium express astir wherever we’re declaring the edit bid.

~~Till Mac OS was up to date successful 2013, location wasn’t~~

Inactive location isn’t immoderate transportable bid crossed GNU and Mac (BSD), arsenic these variants each failed (with an mistake oregon surprising backup information):

sed -i -e ... - plant connected Linux however does not activity connected macOS arsenic it creates -e backups
sed -i '' -e ... - plant connected macOS however fails connected Linux
sed -i='' -e ... - make = backups records-data connected macOS and Linux
sed -i'' -e ... - make -e backups information connected macOS

Moveable resolution

You person fewer choices to accomplish the aforesaid consequence connected Linux and macOS, e.g.:

Usage Perl: perl -i -pe's/old_link/new_link/g' *.
Usage gnu-sed connected macOS (Instal utilizing Homebrew)

# Instal 'gnu-sed' connected macOS utilizing Homebrew brew instal gnu-sed # Usage 'gsed' alternatively of 'sed' connected macOS. gsed -i'' -e 's/hullo/bye/g' my_file.txt

Line: Connected macOS, you might adhd the bin way of gnu-sed containing the sed bid to the Way situation adaptable successful your ammunition configuration record (.zshrc).
It is champion not to bash this, since location whitethorn beryllium scripts that trust connected the macOS constructed-successful interpretation.

You tin adhd an alias for gsed arsenic sed utilizing alias sed=gsed (changing macOS sed with GNU sed) successful your ~/.zshrc. This ought to let you to usage sed “linux-stile” successful your ammunition and volition person nary results connected scripts until they incorporate shopt -s expand_aliases.

If you are utilizing sed successful a book, you tin attempt to automate switching to gsed:

#!/usr/bin/env bash fit -Eeuo pipefail if [[ "$OSTYPE" == "darwin"* ]]; past # Necessitate gnu-sed. if ! [ -x "$(bid -v gsed)" ]; past echo "Mistake: 'gsed' is not istalled." >&2 echo "If you are utilizing Homebrew, instal with 'brew instal gnu-sed'." >&2 exit 1 fi SED_CMD=gsed other SED_CMD=sed fi # Usage '${SED_CMD}' alternatively of 'sed' ${SED_CMD} -i'' -e 's/hullo/bye/g' my_file.txt

You tin briefly fit Way to usage “gnu-sed” sed for a book:

# tally a linux book containing sed with out altering it Way="$(brew --prefix)/decide/gnu-sed/libexec/gnubin:$Way" ./linux_script_using_sed.sh

If you are transcript/pasting linux scripts, you tin alias gsed to sed successful the actual ammunition:

alias sed=gsed sed -i 's/hullo/bye/g' just_a_file.txt

Usage -i '' connected macOS and BSD oregon -i (GNU sed) other

#!/usr/bin/env bash fit -Eeuo pipefail lawsuit "$OSTYPE" successful darwin*|bsd*) echo "Utilizing BSD sed kind" sed_no_backup=( -i '' ) ;; *) echo "Utilizing GNU sed kind" sed_no_backup=( -i ) ;; esac sed ${sed_no_backup[@]} -e 's/hullo/bye/g' my_file.txt