Implement support for personal units library.

With -f one could read an alternative library but it would replace the
standard units library, not add to it. Allow passing -f multiple times
to read all files and merge them together. Passing the empty string,
i.e. -f '' reads the default units library.

This is implemented in at least FreeBSD and Linux.

OK miod

diff --git a/usr.bin/units/units.1 b/usr.bin/units/units.1
index d7a45f7..d9178d4 100644 (file)
--- a/usr.bin/units/units.1
+++ b/usr.bin/units/units.1
@@ -1,4 +1,4 @@
-.\" $OpenBSD: units.1,v 1.27 2022/02/18 10:24:33 jsg Exp $
+.\" $OpenBSD: units.1,v 1.28 2022/12/26 18:52:10 florian Exp $
 .\" converted to new format by deraadt@openbsd.org
 .\"
 .\" Copyright (c) 1993 by Adrian Mariano (adrian@cam.cornell.edu)
@@ -16,7 +16,7 @@
 .\" I would appreciate (though I do not require) receiving a copy of any
 .\" improvements you might make to this program.
 .\"
-.Dd $Mdocdate: February 18 2022 $
+.Dd $Mdocdate: December 26 2022 $
 .Dt UNITS 1
 .Os
 .Sh NAME
@@ -79,6 +79,11 @@ The options are as follows:
 .Bl -tag -width Ds
 .It Fl f Ar filename
 Specifies the name of the units data file to load.
+This option may be specified multiple times.
+The standard units library is read if
+.Ar filename
+is the empty string.
+This allows extending the standard units library with a personal library.
 .It Fl q
 Suppresses prompting of the user for units and the display of statistics
 about the number of units loaded.

diff --git a/usr.bin/units/units.c b/usr.bin/units/units.c
index 98af503..8f93c3a 100644 (file)
--- a/usr.bin/units/units.c
+++ b/usr.bin/units/units.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: units.c,v 1.22 2015/10/09 01:37:09 deraadt Exp $      */
+/*     $OpenBSD: units.c,v 1.23 2022/12/26 18:52:10 florian Exp $      */
 /*     $NetBSD: units.c,v 1.6 1996/04/06 06:01:03 thorpej Exp $        */
 
 /*
@@ -100,7 +100,6 @@ readunits(char *userfile)
        int len, linenum, i;
        FILE *unitfile;
 
-       unitcount = 0;
        linenum = 0;
 
        if (userfile) {
@@ -626,8 +625,7 @@ main(int argc, char **argv)
        struct unittype have, want;
        char havestr[81], wantstr[81];
        int optchar;
-       char *userfile = 0;
-       int quiet = 0;
+       int quiet = 0, units_read = 0;
 
        extern char *optarg;
        extern int optind;
@@ -638,7 +636,8 @@ main(int argc, char **argv)
        while ((optchar = getopt(argc, argv, "vqf:")) != -1) {
                switch (optchar) {
                case 'f':
-                       userfile = optarg;
+                       units_read = 1;
+                       readunits(*optarg == '\0' ? NULL : optarg);
                        break;
                case 'q':
                        quiet = 1;
@@ -662,7 +661,8 @@ main(int argc, char **argv)
        if (argc != 3 && argc != 2 && argc != 0)
                usage();
 
-       readunits(userfile);
+       if (!units_read)
+               readunits(NULL);
 
        if (pledge("stdio", NULL) == -1)
                err(1, "pledge");