About specifying input and output format

[aborruso]

Hi,
I'm a basic user of mlr and I'm becoming mad for stupid thing: specifying input and (especially) output format.

If I run

echo '[{"name":"tom","age":22},{"name":"bianca","age":34}]' | mlr --json --csv cat

I have an error, because I must write --ocsv for output. I lost (I'm stupid :) ) a lot of minutes to figure out how to correct the above command, for two reasons:

• it's not mandatory to specify i and than --ijson for input (it works in both ways). Than for me it had to be the same also for output and I was looking for syntax errors only in the input file and not in the command. For me --csv had to be ok;
• I think that - I could be wrong - that there is not in documentation a sentence like "to specify the output format prepend --o to the format name (i.e. --ocsv, --ojson, etc.) and optionally prepend --i for input one". I think it would be good to have it

Probably the right way is to add dedicated section in the documentation, because mlr option for input and output are many:

• mlr --ijson cat input.json, to set the input as json and to have the default output;
• mlr --json cat input.json, to set the input and output as json;
• mlr --ijson --ocsv cat input.json, to set the input as json and to have csv output;
• mlr --json --ocsv cat input.json, to set the input as json and to have csv output;
• mlr --j2c cat input.json, to set the input as json and to have csv output;
• echo "name=tom,age=22\nname=bianca,age=34" | mlr --ocsv cat, to set csv as output and use the default input format;

Thank you

[johnkerl]

Thanks, I will definitely write this up as an FAQ!

Additionally:

• --ijson --ocsv is what I would recommend
• --json is shorthand for --ijson --ojson
• --foo --obar isn't quite the same as --ifoo --obar in all cases (--pprint --csv argument-parsing oddity [was: double quote handling appears to be broken again] #180).

[johnkerl]

http://johnkerl.org/miller-releases/miller-head/doc/reference.html#Formats

[johnkerl]

fbef04e

831cdd7

[aborruso]

thank you