Treat all integer multiplier suffixes as base-2.

Originally both base-2 and base-10 were supported, but since
there seems to be little need for base-10 in XZ Utils, treat
everything as base-2 and also be more relaxed about the case
of the first letter of the suffix. Now xz will accept e.g.
KiB, Ki, k, K, kB, and KB, and interpret them all as 1024. The
recommended spelling of the suffixes are still KiB, MiB, and GiB.

2 files changed, 51 insertions, 50 deletions

diff --git a/src/xz/util.c b/src/xz/util.c
index dd95fa7a..deb5dcc2 100644
--- a/src/xz/util.c
+++ b/src/xz/util.c
@@ -65,39 +65,32 @@ str_to_uint64(const char *name, const char *value, uint64_t min, uint64_t max)
 	} while (*value >= '0' && *value <= '9');
 
 	if (*value != '\0') {
-		// Look for suffix.
-		static const struct {
-			const char name[4];
-			uint64_t multiplier;
-		} suffixes[] = {
-			{ "k",   UINT64_C(1000) },
-			{ "kB",  UINT64_C(1000) },
-			{ "M",   UINT64_C(1000000) },
-			{ "MB",  UINT64_C(1000000) },
-			{ "G",   UINT64_C(1000000000) },
-			{ "GB",  UINT64_C(1000000000) },
-			{ "Ki",  UINT64_C(1024) },
-			{ "KiB", UINT64_C(1024) },
-			{ "Mi",  UINT64_C(1048576) },
-			{ "MiB", UINT64_C(1048576) },
-			{ "Gi",  UINT64_C(1073741824) },
-			{ "GiB", UINT64_C(1073741824) }
-		};
-
+		// Look for suffix. Originally this supported both base-2
+		// and base-10, but since there seems to be little need
+		// for base-10 in this program, treat everything as base-2
+		// and also be more relaxed about the case of the first
+		// letter of the suffix.
 		uint64_t multiplier = 0;
-		for (size_t i = 0; i < ARRAY_SIZE(suffixes); ++i) {
-			if (strcmp(value, suffixes[i].name) == 0) {
-				multiplier = suffixes[i].multiplier;
-				break;
-			}
-		}
+		if (*value == 'k' || *value == 'K')
+			multiplier = UINT64_C(1) << 10;
+		else if (*value == 'm' || *value == 'M')
+			multiplier = UINT64_C(1) << 20;
+		else if (*value == 'g' || *value == 'G')
+			multiplier = UINT64_C(1) << 30;
+
+		++value;
+
+		// Allow also e.g. Ki, KiB, and KB.
+		if (*value != '\0' && strcmp(value, "i") != 0
+				&& strcmp(value, "iB") != 0
+				&& strcmp(value, "B") != 0)
+			multiplier = 0;
 
 		if (multiplier == 0) {
-			message(V_ERROR, _("%s: Invalid multiplier suffix. "
-					"Valid suffixes:"), value);
-			message_fatal("`k' (10^3), `M' (10^6), `G' (10^9) "
-					"`Ki' (2^10), `Mi' (2^20), "
-					"`Gi' (2^30)");
+			message(V_ERROR, _("%s: Invalid multiplier suffix"),
+					value - 1);
+			message_fatal(_("Valid suffixes are `KiB' (2^10), "
+					"`MiB' (2^20), and `GiB' (2^30)."));
 		}
 
 		// Don't overflow here either.
diff --git a/src/xz/xz.1 b/src/xz/xz.1
index aba0a693..b60353d0 100644
--- a/src/xz/xz.1
+++ b/src/xz/xz.1
@@ -238,28 +238,36 @@ In most places where an integer argument is expected, an optional suffix
 is supported to easily indicate large integers. There must be no space
 between the integer and the suffix.
 .TP
-.BR k " or " kB
-The integer is multiplied by 1,000 (10^3). For example,
-.B "5k"
-or
-.B "5kB"
-equals
-.BR "5000" .
-.TP
-.BR Ki " or " KiB
-The integer is multiplied by 1,024 (2^10).
-.TP
-.BR M " or " MB
-The integer is multiplied by 1,000,000 (10^6).
-.TP
-.BR Mi " or " MiB
-The integer is multiplied by 1,048,576 (2^20).
+.B KiB
+The integer is multiplied by 1,024 (2^10). Also
+.BR Ki ,
+.BR k ,
+.BR kB ,
+.BR K ,
+and
+.B KB
+are accepted as synonyms for
+.BR KiB .
 .TP
-.BR G " or " GB
-The integer is multiplied by 1,000,000,000 (10^9).
+.B MiB
+The integer is multiplied by 1,048,576 (2^20). Also
+.BR Mi ,
+.BR m ,
+.BR M ,
+and
+.B MB
+are accepted as synonyms for
+.BR MiB .
 .TP
-.BR Gi " or " GiB
-The integer is multiplied by 1,073,741,824 (2^30).
+.B GiB
+The integer is multiplied by 1,073,741,824 (2^30). Also
+.BR Gi ,
+.BR g ,
+.BR G ,
+and
+.B GB
+are accepted as synonyms for
+.BR GiB .
 .PP
 A special value
 .B max