Previously, there were two mostly-identical value printers -- one in
`libexpr/eval.cc` (which didn't force values) and one in
`libcmd/repl.cc` (which did force values and also printed ANSI color
codes).
This PR unifies both of these printers into `print.cc` and provides a
`PrintOptions` struct for controlling the output, which allows for
toggling whether values are forced, whether repeated values are tracked,
and whether ANSI color codes are displayed.
Additionally, `PrintOptions` allows tuning the maximum number of
attributes, list items, and bytes in a string that will be displayed;
this makes it ideal for contexts where printing too much output (e.g.
all of Nixpkgs) is distracting. (As requested by @roberth in
https://github.com/NixOS/nix/pull/9554#issuecomment-1845095735)
Please read the tests for example output.
Future work:
- It would be nice to provide this function as a builtin, perhaps
`builtins.toStringDebug` -- a printing function that never fails would
be useful when debugging Nix code.
- It would be nice to support customizing `PrintOptions` members on the
command line, e.g. `--option to-string-max-attrs 1000`.
(cherry picked from commit 0fa08b451682fb3311fe58112ff05c4fe5bee3a4, )
===
Restore ambiguous value printer for `nix-instantiate`
The Nix team has requested that this output format remain unchanged.
I've added a warning to the man page explaining that `nix-instantiate
--eval` output will not parse correctly in many situations.
(cherry picked from commit df84dd4d8dd3fd6381ac2ca3064432ab31a16b79)
Change-Id: I7cca6b4b53cd0642f2d49af657d5676a8554c9f8
nix-shell: support single quotes in shebangs, fix whitespace parsing
(cherry picked from commit 3b99c6291377cbd22607896af9dfafa857d2f2dc)
Change-Id: I2a431b21c3467eefa1ef95d5a36d672f45b6937a
do not show configuration override flags for each command
(cherry picked from commit f89b84919c1a5c796512c50311821e7779b3678b)
Change-Id: Ib98b739bd6c9a1e94f94a78a47d84d72e435e7c0
this is a pure reformatting, contents were not changed
one sentence per line makes reviewing diffs and making suggestions much
more convenient. the indentation was an artifat of the DocBook
migration.
this is a how-to guide which should not be in the reference manual.
it also refers to `nix-env`, which should not be the first thing readers
of the reference manual encounter, as it behaves very differently in
spirit from the rest of Nix.
slightly reword the documentation to be more concise and informative.
- Improved API docs from comment
- Exit codes are for `nix-build`, not just `nix-store --release`
- Make note in tests so the magic numbers are not surprising
Picking up where #8387 left off.
Deleting store info corrected (there is a foot-gun in Nix with
`--delete-generations old`!)
Also a few things are cleaned up based on feedback.
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
Co-authored-by: Eelco Dolstra <edolstra@gmail.com>
Add support to --list-generations
as another way to say
nix-env --profile /nix/var/nix/profiles/per-user/$USER/channels --list-generations
the way we did for nix-channel --rollback [generation id]
e.g. nix-env -e subversion => nix-env --uninstall subversion
The aim is to make the documentation less cryptic for newcomers and the
long options are more self-documenting.
The change was made with the following script:
<https://github.com/aschmolck/convert-short-nix-opts-to-long-ones>
and sanity checked visually.
This gives some more context and should clarify why it works that way.
Also link it from the section on `NIX_USER_CONF_FILES`.
Co-authored-by: John Ericson <git@JohnEricson.me>
it's probably better not to show the manifest file documentation in the
command-specific pages, because these are implementation details that are not really practically useful.
this means no additional hassle for building the manual, but clutters
the table of contents a bit.
eldritch horrors
