Module Name: src
Committed By: kre
Date: Sat Sep 21 20:48:51 UTC 2024
Modified Files:
src/bin/sh: options.c sh.1
src/tests/bin/sh: t_shift.sh
Log Message:
In !TINYPROG versions of sh, make the builtin "shift" builtin command
perform a rotate instead or shift if given a numeric arg (which is
otherwise an error).
"set -- a b c; shift -1; echo $*" will echo "c a b".
While here, make the shift builtin comply with POSIX, and accept
(and ignore) a '--' arg before the shift (or rotate) count.
Document the variant of shift in sh(1)
Adapt the shell test for shift to not expect "shift -1" to be an
error, test that rotate works as expected, and include some tests
that use the (useless, but required) "--" arg.
To generate a diff of this commit:
cvs rdiff -u -r1.59 -r1.60 src/bin/sh/options.c
cvs rdiff -u -r1.263 -r1.264 src/bin/sh/sh.1
cvs rdiff -u -r1.2 -r1.3 src/tests/bin/sh/t_shift.sh
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/bin/sh/options.c
diff -u src/bin/sh/options.c:1.59 src/bin/sh/options.c:1.60
--- src/bin/sh/options.c:1.59 Fri Jul 12 07:30:30 2024
+++ src/bin/sh/options.c Sat Sep 21 20:48:50 2024
@@ -1,4 +1,4 @@
-/* $NetBSD: options.c,v 1.59 2024/07/12 07:30:30 kre Exp $ */
+/* $NetBSD: options.c,v 1.60 2024/09/21 20:48:50 kre Exp $ */
/*-
* Copyright (c) 1991, 1993
@@ -37,7 +37,7 @@
#if 0
static char sccsid[] = "@(#)options.c 8.2 (Berkeley) 5/4/95";
#else
-__RCSID("$NetBSD: options.c,v 1.59 2024/07/12 07:30:30 kre Exp $");
+__RCSID("$NetBSD: options.c,v 1.60 2024/09/21 20:48:50 kre Exp $");
#endif
#endif /* not lint */
@@ -415,17 +415,78 @@ freeparam(volatile struct shparam *param
* The shift builtin command.
*/
+#ifndef TINY
+/* first the rotate variant */
+static inline int
+rotatecmd(int argc, char **argv)
+{
+ int n;
+ char **ap1, **ap2, **ss;
+
+ (void) nextopt(NULL); /* ignore '--' as leading option */
+
+ /*
+ * half this is just in case it ever becomes
+ * a separate named command, while it remains
+ * puerly an inline inside shift, the compiler
+ * should optimise most of it to nothingness
+ */
+ if (argptr[0] && argptr[1])
+ error("Usage: rotate [n]");
+ n = 1;
+ if (*argptr) {
+ if (**argptr == '-')
+ n = number(*argptr + 1);
+ else /* anti-clockwise n == clockwise $# - n */
+ n = shellparam.nparam - number(*argptr);
+ }
+
+ if (n == 0 || n == shellparam.nparam) /* nothing to do */
+ return 0;
+
+ if (n < 0 || n > shellparam.nparam)
+ error("can't rotate that many");
+
+ ap2 = ss = (char **)stalloc(n * sizeof(char *));
+ INTOFF;
+ for (ap1 = shellparam.p + shellparam.nparam - n;
+ ap1 < shellparam.p + shellparam.nparam; )
+ *ap2++ = *ap1++;
+ for (ap2 = shellparam.p + shellparam.nparam, ap1 = ap2 - n;
+ ap1 > shellparam.p; )
+ *--ap2 = *--ap1;
+ for (ap1 = ss + n; ap1 > ss; )
+ *--ap2 = *--ap1;
+ shellparam.optnext = NULL;
+ INTON;
+ stunalloc(ss);
+
+ return 0;
+}
+#endif
+
int
shiftcmd(int argc, char **argv)
{
int n;
char **ap1, **ap2;
- if (argc > 2)
+ (void) nextopt(NULL); /* ignore '--' as leading option */
+
+ if (argptr[0] && argptr[1])
error("Usage: shift [n]");
+
+#ifndef TINY
+ if (*argptr && **argptr == '-') {
+ argptr = argv + 1; /* reinit nextopt() */
+ optptr = NULL;
+ return rotatecmd(argc, argv);
+ }
+#endif
+
n = 1;
- if (argc > 1)
- n = number(argv[1]);
+ if (*argptr)
+ n = number(*argptr);
if (n > shellparam.nparam)
error("can't shift that many");
INTOFF;
Index: src/bin/sh/sh.1
diff -u src/bin/sh/sh.1:1.263 src/bin/sh/sh.1:1.264
--- src/bin/sh/sh.1:1.263 Sat Aug 10 19:21:32 2024
+++ src/bin/sh/sh.1 Sat Sep 21 20:48:50 2024
@@ -1,4 +1,4 @@
-.\" $NetBSD: sh.1,v 1.263 2024/08/10 19:21:32 uwe Exp $
+.\" $NetBSD: sh.1,v 1.264 2024/09/21 20:48:50 kre Exp $
.\" Copyright (c) 1991, 1993
.\" The Regents of the University of California. All rights reserved.
.\"
@@ -3924,12 +3924,18 @@ parameters.)
.\"
.Pp
.It Ic shift Op Ar n
-Shift the positional parameters
-.Ar n
-times.
If
-.Ar n
+.Ar n ,
+which must be a decimal integer,
is omitted, 1 is assumed.
+.Pp
+If
+.Ar n
+is unsigned
+.Pq or omitted
+shift the positional parameters
+.Ar n
+times.
Each
.Ic shift
sets the value of
@@ -3944,12 +3950,81 @@ and so on, decreasing
the value of
.Li $#
by one.
-The shift count must be less than or equal to the number of
-positional parameters (
-.Dq Li $# )
+The shift count
+.Pq Ar n
+must be less than or equal to the number of
+positional parameters
+.Pq Dq Li $#
before the shift.
+A shift of
+.Li $#
+positions is equivalent to
+.Dq Li set\ Ns Fl Fl
+and results in unsetting all of the positional parameters
+and setting
+.Li $#
+to zero.
+The command
+.Dq Li shift\ 0
+does not alter
+.Li $#
+or any of the positional parameters.
+.Pp
+If
+.Ar n
+is negative, then the
+.Ic shift
+becomes a clockwise rotation,
+.Ar \&\-n
+times.
+The absolute value of
+.Ar n
+must be less than or equal to
+.Li $#
+.Pq the number of set positional parameters .
+Each rotation sets the value of
+.Li $1
+to the previous value of
+.Li ${$#}
+(if that were valid syntax) \(en the previous last positional parameter,
+sets
+.Li $2
+to the previous value of
+.Li $1 ,
+the value of
+.Li $3
+to the previous value of
+.Li $2 ,
+and so on, with the new last positional parameter becoming
+what was previously the penultimate positional parameter.
+The value of
+.Li $#
+is not altered.
+Shifts of
+.Li \&\-0
+and
+.Li \&\-$#
+are no-ops.
+The command sequence:
+.Dl shift\ \-n;\ shift\ n
+unsets the final
+.Ar n
+positional parameters.
+.Pp
+An anti-clockwise rotation of
+.Ar n
+places
+.Pq 0\ <=\ Ns Ar n Ns \ <=\ $#
+can be achieved using
+.Dq Li shift\ \-$(($#\ \-\ n)) .
+The command
+.Dq Li shift\ \-$(($#\ \-\ 1))
+is equivalent to, but much faster than:
+.Dl set Fl Fl \&\ Ns Do $@ Dc Do $1 Dc ; shift 1
.\"
.Pp
+The exit status is 0 if no error occurs, otherwise greater than 0.
+.Pp
.It Ic specialvar Ar variable ...
For each
.Ar variable
Index: src/tests/bin/sh/t_shift.sh
diff -u src/tests/bin/sh/t_shift.sh:1.2 src/tests/bin/sh/t_shift.sh:1.3
--- src/tests/bin/sh/t_shift.sh:1.2 Tue May 17 09:05:14 2016
+++ src/tests/bin/sh/t_shift.sh Sat Sep 21 20:48:50 2024
@@ -1,4 +1,4 @@
-# $NetBSD: t_shift.sh,v 1.2 2016/05/17 09:05:14 kre Exp $
+# $NetBSD: t_shift.sh,v 1.3 2024/09/21 20:48:50 kre Exp $
#
# Copyright (c) 2016 The NetBSD Foundation, Inc.
# All rights reserved.
@@ -35,8 +35,10 @@ basic_shift_test_body() {
for a in \
"one-arg::0:one-arg" \
+ "one-arg:--:0:one-arg" \
"one-arg:1:0:one-arg" \
- "one-arg:0:1 one-arg" \
+ "one-arg:-- 1:0:one-arg" \
+ "one-arg:-- 0:1 one-arg" \
"a b c::2 b c:a" \
"a b c:1:2 b c:a" \
"a b c:2:1 c:a:b" \
@@ -68,6 +70,39 @@ basic_shift_test_body() {
'set -- a b c d e;while [ $# -gt 0 ];do shift||echo ERR;done;echo complete'
}
+atf_test_case basic_rotate
+basic_rotate_head() {
+ atf_set "descr" "Test correct operation of valid rotates"
+}
+basic_rotate_body() {
+
+ for a in \
+ "one-arg:-0:1 one-arg" \
+ "one-arg:-1:1 one-arg" \
+ "one-arg:-- -1:1 one-arg" \
+ "a b c:-1:3 c a b" \
+ "a b c:-2:3 b c a" \
+ "a b c:-3:3 a b c" \
+ "a b c:-- -3:3 a b c" \
+ "a b c:-0:3 a b c" \
+ "a b c d e f g h i j k l m n o:-1:15 o a b c d e f g h i j k l m n" \
+ "a b c d e f g h i j k l m n o:-2:15 n o a b c d e f g h i j k l m" \
+ "a b c d e f g h i j k l m n o:-9:15 g h i j k l m n o a b c d e f" \
+ "a b c d e f g h i j k l m n o:-13:15 c d e f g h i j k l m n o a b" \
+ "a b c d e f g h i j k l m n o:-14:15 b c d e f g h i j k l m n o a" \
+ "a b c d e f g h i j k l m n o:-15:15 a b c d e f g h i j k l m n o"
+ do
+ oIFS="${IFS}"
+ IFS=:; set -- $a
+ IFS="${oIFS}"
+
+ init="$1"; n="$2"; res="$3"; shift 3
+
+ atf_check -s exit:0 -o "match:${res}" -e empty \
+ ${TEST_SH} -c "set -- ${init}; shift $n;"' echo "$# $*"'
+ done
+}
+
atf_test_case excessive_shift
excessive_shift_head() {
atf_set "descr" "Test acceptable operation of shift too many"
@@ -115,6 +150,34 @@ excessive_shift_body() {
done
}
+atf_test_case excessive_rotate
+excessive_rotate_head() {
+ atf_set "descr" "Test acceptable operation of rotate too many"
+}
+
+excessive_rotate_body() {
+ for a in \
+ "one-arg:2" \
+ "one-arg:4" \
+ "one-arg:13" \
+ "one two:3" \
+ "one two:7" \
+ "one two three four five:6" \
+ "I II III IV V VI VII VIII IX X XI XII XIII XIV XV:16" \
+ "I II III IV V VI VII VIII IX X XI XII XIII XIV XV:17" \
+ "I II III IV V VI VII VIII IX X XI XII XIII XIV XV:30" \
+ "I II III IV V VI VII VIII IX X XI XII XIII XIV XV:9999"
+ do
+ oIFS="${IFS}"
+ IFS=:; set -- $a
+ IFS="${oIFS}"
+
+ atf_check -s not-exit:0 -o match:OK -o not-match:ERR \
+ -e ignore ${TEST_SH} -c \
+ "set -- $1 ;echo OK:$#:-$2; shift -$2 && echo ERR"
+ done
+}
+
atf_test_case function_shift
function_shift_head() {
atf_set "descr" "Test that shift in a function does not affect outside"
@@ -149,10 +212,12 @@ non_numeric_shift_head() {
non_numeric_shift_body() {
# there are 9 args set, 010 is 8 if parsed octal, 10 decimal
- for a in a I 0x12 010 5V -1 ' ' '' +1 ' 1'
+ for a in a I 0x12 010 5V ' ' '' +1 ' 1'
do
atf_check -s not-exit:0 -o empty -e ignore ${TEST_SH} -c \
"set -- a b c d e f g h i; shift '$a' && echo ERROR"
+ atf_check -s not-exit:0 -o empty -e ignore ${TEST_SH} -c \
+ "set -- a b c d e f g h i; shift -- '$a' && echo ERROR"
done
}
@@ -165,7 +230,7 @@ too_many_args_head() {
too_many_args_body() {
# This tests the bug in PR bin/50896 is fixed
- for a in "1 1" "1 0" "1 2 3" "1 foo" "1 --" "-- 1"
+ for a in "1 1" "1 0" "1 2 3" "1 foo" "1 --" "-- 1 2" "-1 2"
do
atf_check -s not-exit:0 -o empty -e not-empty ${TEST_SH} -c \
" set -- a b c d; shift ${a} ; echo FAILED "
@@ -178,4 +243,6 @@ atf_init_test_cases() {
atf_add_test_case function_shift
atf_add_test_case non_numeric_shift
atf_add_test_case too_many_args
+ atf_add_test_case basic_rotate
+ atf_add_test_case excessive_rotate
}
