Caltech Library logo

USAGE

jsonrange [OPTIONS] [DOT_PATH_EXPRESSION]

DESCRIPTION

jsonrange returns returns a range of values based on the JSON structure being read and options applied. Without options the JSON structure is read from standard input and writes a list of keys to standard out. Keys are either attribute names or for arrays the index position (counting form zero). If a DOT_PATH_EXPRESSION is included on the command line then that is used to generate the results. Using options to can choose to read the JSON data structure from a file, write the output to a file as well as display values instead of keys. a list of “keys” of an index or map in JSON.

Using options it can also return a list of values. The JSON object is read from standard in and the resulting list is normally written to standard out. There are options to read or write to files. Additional parameters are assumed to be a dot path notation select the parts of the JSON data structure you want from the range.

DOT_PATH_EXPRESSION is a dot path stale expression indicating what you want range over. E.g.

The path can be chained together

OPTIONS

Below are a set of options available.

    -d, -delimiter       set delimiter for range output
    -examples            display example(s)
    -generate-manpage    generate man page
    -generate-markdown   generate markdown docs
    -h, -help            display help
    -i, -input           read JSON from file
    -l, -license         display license
    -last                return the index of the last element in list (e.g. length - 1)
    -length              return the number of keys or values
    -limit               limit the number of items output
    -nl, -newline        if true add a trailing newline
    -o, -output          write to output file
    -quiet               suppress error messages
    -v, -version         display version
    -values              return the values instead of the keys

EXAMPLES

Working with a map

echo '{"name": "Doe, Jane", "email":"jane.doe@example.org", "age": 42}' \
   | jsonrange

This would yield

name
email
age

Using the -values option on a map

echo '{"name": "Doe, Jane", "email":"jane.doe@example.org", "age": 42}' \
  | jsonrange -values

This would yield

"Doe, Jane"
"jane.doe@example.org"
42

Working with an array

echo '["one", 2, {"label":"three","value":3}]' | jsonrange

would yield

0
1
2

Using the -values option on the same array

echo '["one", 2, {"label":"three","value":3}]' | jsonrange -values

would yield

one
2
{"label":"three","value":3}

Checking the length of a map or array or number of keys in map

echo '["one","two","three"]' | jsonrange -length

would yield

3

Check for the index of last element

echo '["one","two","three"]' | jsonrange -last

would yield

2

Check for the index value of last element

echo '["one","two","three"]' | jsonrange -values -last

would yield

"three"

Limitting the number of items returned

echo '[10,20,30,40,50]' | %!s(MISSING) -limit 2

would yield

1
2

Limitting the number of values returned

echo '[10,20,30,40,50]' | %!s(MISSING) -values -limit 2

would yield

10
20

jsonrange v0.0.25