Can not set negative integer value in command line

[ydcool]

Describe the bug
Can not set negative value in command line , it'll treated as a command line flag rather than a value, and the escape character does not work.

To Reproduce
Steps to reproduce the behavior:

#  dasel put int -p toml -f /etc/containerd/config.toml '.oom_score' '-900'
Error: unknown shorthand flag: '9' in -900

#  dasel put int -p toml -f /etc/containerd/config.toml '.oom_score' "\-900"
Error: could not parse int [\-900]: strconv.ParseInt: parsing "\\-900": invalid syntax
Usage:
  dasel put int -f <file> -s <selector> <value> [flags]

Flags:
  -h, --help   help for int

Global Flags:
  -f, --file string       The file to query.
  -m, --multiple          Select multiple results.
  -o, --out string        Output destination.
  -p, --parser string     Shorthand for -r FORMAT -w FORMAT.
  -r, --read string       The parser to use when reading.
  -s, --selector string   The selector to use when querying the data structure.
  -w, --write string      The parser to use when writing.

Error: could not parse int [\-900]: strconv.ParseInt: parsing "\\-900": invalid syntax

Desktop (please complete the following information):

• OS: linux/ubuntu 18.06
• Version: dasel version v1.11.0-2-gbe51ab2

[TomWright]

Thanks for raising this @ydcool.

I can confirm this is still an issue in the latest version: dasel version v1.13.6.

This is related to #101, and is caused by: https://github.com/spf13/pflag/blob/85dd5c8bc61cfa382fecd072378089d4e856579d/flag.go#L962

The code causing this is out of my control (without a PR at least) but in the short term I could introduce a workaround in the form of:

dasel put int -p toml -f /etc/containerd/config.toml' '.oom_score' 'n900'

This would mean that throughout dasel, when attempting to parse an int it would check to see if it starts with an n and convert that to a negative number.

I'm going to raise an issue regarding the above and see if I can get the root cause solved.

[TomWright]

The related issue is here: spf13/pflag#311

[ydcool]

Nice, I'll also keep an eye on it to see if I can help.

[ydcool]

I noticed that grep command can handle the escape charather, so it's also due to the upstream problem?

# cat /etc/containerd/config.toml | grep '-900'
Usage: grep [OPTION]... PATTERN [FILE]...
Try 'grep --help' for more information.

# cat /etc/containerd/config.toml | grep '\-900'
oom_score = -900

[TomWright]

Yes that's correct. Cobra and pflag control the input to dasel and they don't seem to arguments beginning with a dash very well.

[TomWright]

On a side note, it seems that escaping the dash does bypass the pflag validation issue, but then the resulting string of \-900 doesn't parse as a valid int.

Perhaps I could left trim any escape characters when parsing integers.

[TomWright]

I can't just deal with integers here - it's a wider issue.

echo '{"items": []}' | dasel put string -p json '.items.[]' '-thing'
Error: unknown shorthand flag: 't' in -thing

[TomWright]

Hey @ydcool,

Since this is a wider issue and I'm getting no response from the upstream supporter I've added a -v, --value flag that should function as a workaround:

echo '{"number":100}' | dasel put int -p json -v -200 '.number'

Or in your case:

dasel put int -p toml -f /etc/containerd/config.toml -v '-900' '.oom_score'

This is currently available on the development build which is accessible via:

1. Installing from source:

go install github.com/tomwright/dasel/cmd/dasel@master

2. Running from docker

echo '{"name": "Tom"}' | docker run -i --rm ghcr.io/tomwright/dasel:development put int -p json -v '-900' '.age'
{
  "age": -900,
  "name": "Tom"
}

[ydcool]

-v, --value works well, it's still a nice solution : )

[TomWright]

This is now released under v1.20.0