hush: getopts builtin

function                                             old     new   delta
builtin_getopts                                        -     271    +271
bltins1                                              372     384     +12
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 1/0 up/down: 283/0)             Total: 283 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

7 files changed, 212 insertions, 2 deletions

diff --git a/shell/ash_test/ash-getopts/getopt_positional.right b/shell/ash_test/ash-getopts/getopt_positional.right
new file mode 100644
index 000000000..37d0ec845
--- /dev/null
+++ b/shell/ash_test/ash-getopts/getopt_positional.right
@@ -0,0 +1,6 @@
+*** no OPTIND, optstring:'we' args:-q -w -e r -t -y
+Illegal option -q
+var:'?' OPTIND:2
+var:'w' OPTIND:3
+var:'e' OPTIND:4
+exited: var:'?' OPTIND:4
diff --git a/shell/ash_test/ash-getopts/getopt_positional.tests b/shell/ash_test/ash-getopts/getopt_positional.tests
new file mode 100755
index 000000000..a5404a2a0
--- /dev/null
+++ b/shell/ash_test/ash-getopts/getopt_positional.tests
@@ -0,0 +1,8 @@
+set -- -q -w -e r -t -y
+echo "*** no OPTIND, optstring:'we' args:$*"
+var=QWERTY
+while getopts "we" var; do
+	echo "var:'$var' OPTIND:$OPTIND"
+done
+# unfortunately, "rc:0" is shown since while's overall exitcode is "success"
+echo "exited: var:'$var' OPTIND:$OPTIND"
diff --git a/shell/hush.c b/shell/hush.c
index b53d1dcfb..dba12c12e 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -48,7 +48,7 @@
  *      tilde expansion
  *      aliases
  *      builtins mandated by standards we don't support:
- *          [un]alias, command, fc, getopts:
+ *          [un]alias, command, fc:
  *          command -v CMD: print "/path/to/CMD"
  *              prints "CMD" for builtins
  *              prints "alias ALIAS='EXPANSION'" for aliases
@@ -58,7 +58,6 @@
  *              (can use this to override standalone shell as well)
  *              -p: use default $PATH
  *          command BLTIN: disables special-ness (e.g. errors do not abort)
- *          getopts: getopt() for shells
  *          fc -l[nr] [BEG] [END]: list range of commands in history
  *          fc [-e EDITOR] [BEG] [END]: edit/rerun range of commands
  *          fc -s [PAT=REP] [CMD]: rerun CMD, replacing PAT with REP
@@ -294,6 +293,11 @@
 //config:	default y
 //config:	depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
 //config:
+//config:config HUSH_GETOPTS
+//config:	bool "getopts builtin"
+//config:	default y
+//config:	depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
+//config:
 //config:config HUSH_MEMLEAK
 //config:	bool "memleak builtin (debugging)"
 //config:	default n
@@ -983,6 +987,9 @@ static int builtin_readonly(char **argv) FAST_FUNC;
 static int builtin_fg_bg(char **argv) FAST_FUNC;
 static int builtin_jobs(char **argv) FAST_FUNC;
 #endif
+#if ENABLE_HUSH_GETOPTS
+static int builtin_getopts(char **argv) FAST_FUNC;
+#endif
 #if ENABLE_HUSH_HELP
 static int builtin_help(char **argv) FAST_FUNC;
 #endif
@@ -1079,6 +1086,9 @@ static const struct built_in_command bltins1[] = {
 #if ENABLE_HUSH_JOB
 	BLTIN("fg"       , builtin_fg_bg   , "Bring job to foreground"),
 #endif
+#if ENABLE_HUSH_GETOPTS
+	BLTIN("getopts"  , builtin_getopts , NULL),
+#endif
 #if ENABLE_HUSH_HELP
 	BLTIN("help"     , builtin_help    , NULL),
 #endif
@@ -9859,6 +9869,69 @@ static int FAST_FUNC builtin_shift(char **argv)
 	return EXIT_FAILURE;
 }
 
+#if ENABLE_HUSH_GETOPTS
+static int FAST_FUNC builtin_getopts(char **argv)
+{
+/*
+TODO:
+if a character is followed by a colon, the option is expected to have
+an argument, which should be separated from it by white space.
+When an option requires an argument, getopts places that argument into
+the variable OPTARG.
+
+If an invalid option is seen, getopts places ? into VAR and, if
+not silent, prints an error message and unsets OPTARG. If
+getopts is silent, the option character found is placed in
+OPTARG and no diagnostic message is printed.
+
+If a required argument is not found, and getopts is not silent,
+a question mark (?) is placed in VAR, OPTARG is unset, and a
+diagnostic message is printed.  If getopts is silent, then a
+colon (:) is placed in VAR and OPTARG is set to the option
+character found.
+
+Test that VAR is a valid variable name?
+*/
+	char cbuf[2];
+	const char *cp, *optstring, *var;
+	int c, exitcode;
+
+	optstring = *++argv;
+	if (!optstring || !(var = *++argv)) {
+		bb_error_msg("usage: getopts OPTSTRING VAR [ARGS]");
+		return EXIT_FAILURE;
+	}
+
+	cp = get_local_var_value("OPTERR");
+	opterr = cp ? atoi(cp) : 1;
+	cp = get_local_var_value("OPTIND");
+	optind = cp ? atoi(cp) : 0;
+
+	/* getopts stops on first non-option. Add "+" to force that */
+	/*if (optstring[0] != '+')*/ {
+		char *s = alloca(strlen(optstring) + 2);
+		sprintf(s, "+%s", optstring);
+		optstring = s;
+	}
+
+	if (argv[1])
+		argv[0] = G.global_argv[0]; /* for error messages */
+	else
+		argv = G.global_argv;
+	c = getopt(string_array_len(argv), argv, optstring);
+	exitcode = EXIT_SUCCESS;
+	if (c < 0) { /* -1: end of options */
+		exitcode = EXIT_FAILURE;
+		c = '?';
+	}
+	cbuf[0] = c;
+	cbuf[1] = '\0';
+	set_local_var_from_halves(var, cbuf);
+	set_local_var_from_halves("OPTIND", utoa(optind));
+	return exitcode;
+}
+#endif
+
 static int FAST_FUNC builtin_source(char **argv)
 {
 	char *arg_path, *filename;
diff --git a/shell/hush_test/hush-getopts/getopt_positional.right b/shell/hush_test/hush-getopts/getopt_positional.right
new file mode 100644
index 000000000..f1c942476
--- /dev/null
+++ b/shell/hush_test/hush-getopts/getopt_positional.right
@@ -0,0 +1,6 @@
+*** no OPTIND, optstring:'we' args:-q -w -e r -t -y
+./getopt_positional.tests: invalid option -- q
+var:'?' OPTIND:2
+var:'w' OPTIND:3
+var:'e' OPTIND:4
+exited: var:'?' OPTIND:4
diff --git a/shell/hush_test/hush-getopts/getopt_positional.tests b/shell/hush_test/hush-getopts/getopt_positional.tests
new file mode 100755
index 000000000..a5404a2a0
--- /dev/null
+++ b/shell/hush_test/hush-getopts/getopt_positional.tests
@@ -0,0 +1,8 @@
+set -- -q -w -e r -t -y
+echo "*** no OPTIND, optstring:'we' args:$*"
+var=QWERTY
+while getopts "we" var; do
+	echo "var:'$var' OPTIND:$OPTIND"
+done
+# unfortunately, "rc:0" is shown since while's overall exitcode is "success"
+echo "exited: var:'$var' OPTIND:$OPTIND"
diff --git a/shell/hush_test/hush-getopts/getopt_simple.right b/shell/hush_test/hush-getopts/getopt_simple.right
new file mode 100644
index 000000000..b4855fa1a
--- /dev/null
+++ b/shell/hush_test/hush-getopts/getopt_simple.right
@@ -0,0 +1,34 @@
+*** no OPTIND, optstring:'ab' args:-a -b c
+var:'a' OPTIND:2
+var:'b' OPTIND:3
+exited: rc:0 var:'?' OPTIND:3
+*** OPTIND=1, optstring:'ab' args:-a -b c
+var:'a' OPTIND:2
+var:'b' OPTIND:3
+exited: rc:0 var:'?' OPTIND:3
+*** OPTIND=0, optstring:'ab' args:-a -b c
+var:'a' OPTIND:2
+var:'b' OPTIND:3
+exited: rc:0 var:'?' OPTIND:3
+*** unset OPTIND, optstring:'ab' args:-a -b c
+var:'a' OPTIND:2
+var:'b' OPTIND:3
+exited: rc:0 var:'?' OPTIND:3
+*** optstring:'ab' args:-a -b c
+1 rc:0 var:'a' OPTIND:2
+2 rc:0 var:'b' OPTIND:3
+3 rc:1 var:'?' OPTIND:3
+*** unset OPTIND, optstring:'ab' args:-a c -c -b d
+var:'a' OPTIND:2
+exited: rc:0 var:'?' OPTIND:2
+*** unset OPTIND, optstring:'ab' args:-a -c -b d
+var:'a' OPTIND:2
+./getopt_simple.tests: invalid option -- c
+var:'?' OPTIND:3
+var:'b' OPTIND:4
+exited: rc:0 var:'?' OPTIND:4
+*** unset OPTIND, OPTERR=0, optstring:'ab' args:-a -c -b d
+var:'a' OPTIND:2
+var:'?' OPTIND:3
+var:'b' OPTIND:4
+exited: rc:0 var:'?' OPTIND:4
diff --git a/shell/hush_test/hush-getopts/getopt_simple.tests b/shell/hush_test/hush-getopts/getopt_simple.tests
new file mode 100755
index 000000000..8615ae366
--- /dev/null
+++ b/shell/hush_test/hush-getopts/getopt_simple.tests
@@ -0,0 +1,75 @@
+# Simple usage cases for getopts.
+#
+# OPTIND is either not touched at all (first loop with getopts,
+# relying on shell startup init), or getopts state is reset
+# before new loop with "unset OPTIND", "OPTIND=1" or "OPTIND=0".
+#
+# Each option is a separate argument (no "-abc"). This conceptually
+# needs only $OPTIND to hold getopts state.
+#
+# We check that loop does not stop on unknown option (sets "?"),
+# stops on _first_ non-option argument.
+
+echo "*** no OPTIND, optstring:'ab' args:-a -b c"
+var=QWERTY
+while getopts "ab" var -a -b c; do
+	echo "var:'$var' OPTIND:$OPTIND"
+done
+# unfortunately, "rc:0" is shown since while's overall exitcode is "success"
+echo "exited: rc:$? var:'$var' OPTIND:$OPTIND"
+
+# Resetting behavior =1
+echo "*** OPTIND=1, optstring:'ab' args:-a -b c"
+OPTIND=1
+while getopts "ab" var -a -b c; do
+	echo "var:'$var' OPTIND:$OPTIND"
+done
+echo "exited: rc:$? var:'$var' OPTIND:$OPTIND"
+
+# Resetting behavior =0
+echo "*** OPTIND=0, optstring:'ab' args:-a -b c"
+OPTIND=0
+while getopts "ab" var -a -b c; do
+	echo "var:'$var' OPTIND:$OPTIND"
+done
+echo "exited: rc:$? var:'$var' OPTIND:$OPTIND"
+
+# Resetting behavior "unset"
+echo "*** unset OPTIND, optstring:'ab' args:-a -b c"
+unset OPTIND
+while getopts "ab" var -a -b c; do
+	echo "var:'$var' OPTIND:$OPTIND"
+done
+echo "exited: rc:$? var:'$var' OPTIND:$OPTIND"
+
+# What is the final exitcode?
+echo "*** optstring:'ab' args:-a -b c"
+unset OPTIND
+getopts "ab" var -a -b c; echo "1 rc:$? var:'$var' OPTIND:$OPTIND"
+getopts "ab" var -a -b c; echo "2 rc:$? var:'$var' OPTIND:$OPTIND"
+getopts "ab" var -a -b c; echo "3 rc:$? var:'$var' OPTIND:$OPTIND"
+
+# Where would it stop? c or -c?
+echo "*** unset OPTIND, optstring:'ab' args:-a c -c -b d"
+unset OPTIND
+while getopts "ab" var -a c -c -b d; do
+	echo "var:'$var' OPTIND:$OPTIND"
+done
+echo "exited: rc:$? var:'$var' OPTIND:$OPTIND"
+
+# What happens on unknown option?
+echo "*** unset OPTIND, optstring:'ab' args:-a -c -b d"
+unset OPTIND
+while getopts "ab" var -a -c -b d; do
+	echo "var:'$var' OPTIND:$OPTIND"
+done
+echo "exited: rc:$? var:'$var' OPTIND:$OPTIND"
+
+# ORTERR=0 suppresses error message?
+echo "*** unset OPTIND, OPTERR=0, optstring:'ab' args:-a -c -b d"
+unset OPTIND
+OPTERR=0
+while getopts "ab" var -a -c -b d; do
+	echo "var:'$var' OPTIND:$OPTIND"
+done
+echo "exited: rc:$? var:'$var' OPTIND:$OPTIND"