Edit files in place

With GNU Sed for example you can edit files in place:

-i[SUFFIX], --in-place[=SUFFIX]

       edit files in place (makes backup if SUFFIX supplied)

However I see no option for this with JQ, currently I must do this:

br=$(mktemp)
jq .charlie delta.json > "$br"
mv "$br" delta.json

Here is a workaround, Awk slurp:

jq .firstName alfa.json | awk 'BEGIN{RS="";getline<"-";print>ARGV[1]}' alfa.json

[karelv]

+1

[ipmcc]

+1

[nicowilliams]

Scripting around this is not an option? In shell:

tmpf=$(mktemp --tmpdir=$(dirname $f) -t)
jq ... "$f" > "$tmpf"
mv -f "$tmpf" "$f"

[nicowilliams]

I'm asking why it's not acceptable.

[ipmcc]

By analogy: Would it be acceptable if <insert your favorite word processor here> made you save to a different file every time you wanted to save your document?

It's not that the problem can't be worked around, it's that doing so is cumbersome. The fact that something as fundamentally stream oriented as sed has an in-place option is a pretty good indicator that this is common expectation/desire.

[nicowilliams]

I see. I've generally not bothered with sed's -i option. For me the
problem has been two-fold: a) it is (well, was) not portable enough, b) I
always have to check whether such a tool's in-place update functionality is
documented as working this way (rename into place), because I generally
need atomicity. And then there's Windows (where renames generally don't
work when there's open file handles for the file in question, unless all
the processes that opened it used an option to allow it).

On Mon, Jun 9, 2014 at 10:23 AM, ipmcc notifications@github.com wrote:

By analogy: Would it be acceptable if made you save to a different file
every time you wanted to save your document?

It's not that the problem can't be worked around, it's that doing so is
cumbersome. The fact that something as stream oriented as sed has an
in-place option is a pretty good indicator that this is common
expectation/desire.

—
Reply to this email directly or view it on GitHub
#105 (comment).

[nicowilliams]

Anyways, I can add this easily. My only concern is to limit the number of
new command-line options. Since this option couldn't be implemented in a
jq program, I'll probably do it. Though perhaps a generic utility to wrap
filters with might be better:

$ inplace some-file command args

which would run the given command with some-file as the standard input
and which would redirect the command's output to a temporary file in the
same directory then rename that into place. That's the Unix philosophy,
after all.

On Mon, Jun 9, 2014 at 10:58 AM, Nico Williams nico@cryptonector.com
wrote:

I see. I've generally not bothered with sed's -i option. For me the
problem has been two-fold: a) it is (well, was) not portable enough, b) I
always have to check whether such a tool's in-place update functionality is
documented as working this way (rename into place), because I generally
need atomicity. And then there's Windows (where renames generally don't
work when there's open file handles for the file in question, unless all
the processes that opened it used an option to allow it).

On Mon, Jun 9, 2014 at 10:23 AM, ipmcc notifications@github.com wrote:

By analogy: Would it be acceptable if made you save to a different file
every time you wanted to save your document?

It's not that the problem can't be worked around, it's that doing so is
cumbersome. The fact that something as stream oriented as sed has an
in-place option is a pretty good indicator that this is common
expectation/desire.

—
Reply to this email directly or view it on GitHub
#105 (comment).

[nicowilliams]

Ah, there's a sponge(1) that almost works this way:

http://joeyh.name/code/moreutils/
http://backreference.org/2011/01/29/in-place-editing-of-files/

I think both, sponge(1) and my idea of an inplace(1) would be very useful
generally and very much in keeping with the Unix philosophy.

Would that work for you?

[nicowilliams]

@svnpenn @ipmcc @karelv

Regardless of how you feel about this issue, what think ye of this:

https://github.com/nicowilliams/inplace

?

[drorata]

Is the -i option available or not? In the linked commit it says that this feature was removed.

[pkoppstein]

@drorata - It was (as best I can tell) never available in any official jq release, and is certainly not available in jq 1.4 or 1.5. It was added as an experimental feature on Jul 20, 2014, and removed on Mar 5, 2015.