JQ is short for Jamshed Qureshi
jq is also a command-line tool for *nix and Windows.
dbohdan 2015-01-29: You can use jq from Tcl, which can be faster than Tcllib JSON you only need a few values from a large JSON blob. It understands complex queries (called "filters") from .weather0.description to paths | map(tostring) | join("/") | unique to the one defined in the module below.
What follows is a small Tcl module to run jq. Note that ::jq::2dict is slower than ::json::json2dict (37 vs. 21 seconds to process a 10 MiB JSON file) and is only provided for a) the convenience of not having to import another package; b) the case when you want your JSON arrays to be converted to dicts with number keys. The latter allows you use dict get uniformly to access data convert from JSON.
# jq-0.2.tm
namespace eval jq {
proc jq {filter data {options {-r}}} {
exec -- jq {*}$options $filter << $data
}
proc 2dict {data} {
jq {
def totcl:
if type == "array" then
# Convert array to object with keys 0, 1, 2... and process
# it as object.
[range(0;length) as $i
| {key: $i | tostring, value: .[$i]}]
| from_entries
| totcl
elif type == "object" then
.
| to_entries
| map("{\(.key)} {\(.value | totcl)}")
| join(" ")
else
tostring
| split("{") | join ("\\{")
| split("}") | join ("\\}")
end;
. | totcl
} $data
}
}dbohdan: I hope Jamshed doesn't mind me using this page. If he objects I will create a separate page for jq the program.