installed on your computer†.
† Assuming an operating system with a fairly featureful, and
- Posix‐compliant, development setup (e·g, macOS).
+ Posix‐compliant, development setup (e·g, Macintosh ≥ version 10.8).
In fact, on Linux you will probably need to install a few programs:
`libxml2-utils`, `xsltproc`, `sharutils`, and `pax`.
## Prerequisites
In most cases, ⛩️📰 书社 aims to require only functionality which is
- present in all Posix‐compliant operating systems.
+ present in all Posix‐compliant (`POSIX.1-2001`) operating systems.
There are a few exceptions.
Details on particular programs are given below; if a program is not
listed, it is assumed that any Posix‐compliant implementation will
work.
+### `diff`
+
+This is a Posix utility, but ⛩️📰 书社 depends on functionality
+ introduced after `POSIX.1-2001` (the `-u` option, introduced in
+ `POSIX.1-2008`).
+Macintosh systems somewhat interestingly implement this option
+ correctly in legacy mode (`COMMAND_MODE=legacy`) but incorrectly by
+ default (despite claiming `POSIX.1-2008` conformance for this
+ utility).
+[Note this erroneous comment claiming nanosecond & timezone are
+ extensions rather than standardized.][rdar-92753335]
+Despite this, the default Macintosh implementation will still work with
+ ⛩️📰 书社, with the caveat that the timestamp will only include a
+ fractional component when a Posix⹀compliant (e·g, Macintosh legacy or
+ G·N·U) implementation is used.
+
### `file`
-This is a Posix utility, but ⛩️📰 书社 currently depends on
- unspecified behaviour.
+This is a Posix utility, but it was considered optional in
+ `POSIX.1-2001` (altho it was made mandatory in `POSIX.1-2008`) and
+ ⛩️📰 书社 currently depends on unspecified behaviour.
It requires support for the following additional options :—
- **`-C`**, when supplied with `-m`, must be useable to compile a
### `make`
-This is a Posix utility, but ⛩️📰 书社 currently depends on
- unspecified behaviour.
+This is a Posix utility, but it is considered an optional Software
+ Development utility and ⛩️📰 书社 currently depends on unspecified
+ behaviour.
⛩️📰 书社 requires specifically the G·N·U version of `make`, and
depends on functionality present in version 3.81 or later.
It is not expected to work in previous versions, or with other
### `pax`
-This is a Posix utility, but not included in the Linux Standard Base or
- installed by default in many distributions.
-Only `ustar` format support is required.
+This is a Posix utility, but it is not included in the Linux Standard
+ Base or installed by default in many distributions.
+⛩️📰 书社 only requires support for the `ustar` format.
### `uudecode` and `uuencode`
-These are Posix utilities, but not included in the Linux Standard Base
- or installed by default in many distributions.
+These are Posix utilities, but they were considered optional in
+ `POSIX.1-2001` (altho they are made mandatory in `POSIX.1-2008`) and
+ they are not included in the Linux Standard Base or installed by
+ default in many distributions.
The G·N·U [Sharutils](https://www.gnu.org/software/sharutils/) package
- can be installed to access them.
+ provides one implementation.
### `xmlcatalog` and `xmllint`
These are not a Posix utilities.
-They is a part of `libxml2`, but may need to be installed separately
- (e·g by the name `libxml2-utils`).
+They are a part of `libxml2`, but may need to be installed separately
+ on some platforms (e·g by the name `libxml2-utils`).
### `xsltproc`
This is not a Posix utility.
-It is a part of `libxslt`, but may need to be installed separately.
+It is a part of `libxslt`, but may need to be installed separately on
+ some platforms.
## Basic Usage
- `awk`
- `cat`
+- `cd`
- `cksum`
- `cp`
- `date`
+- `diff`
- `file`
- `find`
- `git` (optional; set `GIT=` to disable)
- `grep`
- `ln`
-- `ls`
- `mkdir`
- `mv`
- `od`
The current version of the source files (default: derived from the
current git tag/branch/commit).
+- **`QUIET`:**
+ If this variable has a value, informative messages will not be
+ printed (default: empty).
+ Informative messages print to stderr, not stdout, so disabling them
+ usually shouldn’t be necessary.
+ This does not (cannot) disable messages from Make itself, for which
+ the `-s`, `--silent` ∕ `--quiet` Make option is more likely to be
+ useful.
+
- **`VERBOSE`:**
If this variable has a value, every recipe instruction will be
printed when it runs (default: empty).
- **`SRCTIME`:**
The time at which the source file was last modified.
- Due to limitations in Posix, this time will only have minute
- precision if the file was modified in the last six months, and will
- only have day precision if the file is older.
- Users should not expect this value to be particularly stable.
- **`THISREV`:**
The value of the `THISREV` variable (if present).
[REUSE]: <https://reuse.software/spec/>
[draft-phillips-record-jar-01]: <https://datatracker.ietf.org/doc/html/draft-phillips-record-jar-01>
+[rdar-92753335]: <https://github.com/apple-oss-distributions/patch_cmds/blob/5084833f90df1b0e0924ea56f94c0199b3b8bbc6/diff/diffreg.c#L1800-L1808>
Lady’s Gitweb / Shushe / blobdiff