xargs: simplify option parsing

1 files changed, 91 insertions, 116 deletions

diff --git a/findutils/xargs.c b/findutils/xargs.c
index d067a3f..b6a154f 100644
--- a/findutils/xargs.c
+++ b/findutils/xargs.c
@@ -45,54 +45,52 @@
 #endif
 
 /*
-   This function have special algorithm.
-   Don`t use fork and include to main!
+   This function has special algorithm.
+   Don't use fork and include to main!
 */
 static int xargs_exec(char *const *args)
 {
 	pid_t p;
 	volatile int exec_errno = 0;    /* shared vfork stack */
+	int status;
 
-	if ((p = vfork()) >= 0) {
-		if (p == 0) {
-			/* vfork -- child */
-			execvp(args[0], args);
-			exec_errno = errno;     /* set error to shared stack */
-			_exit(1);
-		} else {
-			/* vfork -- parent */
-			int status;
-
-			while (wait(&status) == (pid_t) - 1)
-				if (errno != EINTR)
-					break;
-			if (exec_errno) {
-				errno = exec_errno;
-				bb_perror_msg("%s", args[0]);
-				return exec_errno == ENOENT ? 127 : 126;
-			} else {
-				if (WEXITSTATUS(status) == 255) {
-					bb_error_msg("%s: exited with status 255; aborting", args[0]);
-					return 124;
-				}
-				if (WIFSTOPPED(status)) {
-					bb_error_msg("%s: stopped by signal %d",
-						args[0], WSTOPSIG(status));
-					return 125;
-				}
-				if (WIFSIGNALED(status)) {
-					bb_error_msg("%s: terminated by signal %d",
-						args[0], WTERMSIG(status));
-					return 125;
-				}
-				if (WEXITSTATUS(status) != 0)
-					return 123;
-				return 0;
-			}
-		}
-	} else {
+	p = vfork();
+	if (p < 0)
 		bb_perror_msg_and_die("vfork");
+
+	if (p == 0) {
+		/* vfork -- child */
+		execvp(args[0], args);
+		exec_errno = errno;     /* set error to shared stack */
+		_exit(1);
+	}
+
+	/* vfork -- parent */
+	while (wait(&status) == (pid_t) -1)
+		if (errno != EINTR)
+			break;
+	if (exec_errno) {
+		errno = exec_errno;
+		bb_perror_msg("%s", args[0]);
+		return exec_errno == ENOENT ? 127 : 126;
 	}
+	if (WEXITSTATUS(status) == 255) {
+		bb_error_msg("%s: exited with status 255; aborting", args[0]);
+		return 124;
+	}
+	if (WIFSTOPPED(status)) {
+		bb_error_msg("%s: stopped by signal %d",
+			args[0], WSTOPSIG(status));
+		return 125;
+	}
+	if (WIFSIGNALED(status)) {
+		bb_error_msg("%s: terminated by signal %d",
+			args[0], WTERMSIG(status));
+		return 125;
+	}
+	if (WEXITSTATUS(status))
+		return 123;
+	return 0;
 }
 
 
@@ -105,7 +103,7 @@ typedef struct xlist_s {
 static int eof_stdin_detected;
 
 #define ISBLANK(c) ((c) == ' ' || (c) == '\t')
-#define ISSPACE(c) (ISBLANK (c) || (c) == '\n' || (c) == '\r' \
+#define ISSPACE(c) (ISBLANK(c) || (c) == '\n' || (c) == '\r' \
 		    || (c) == '\f' || (c) == '\v')
 
 #ifdef CONFIG_FEATURE_XARGS_SUPPORT_QUOTES
@@ -304,19 +302,10 @@ static int xargs_ask_confirmation(void)
 		return 1;
 	return 0;
 }
-
-# define OPT_INC_P 1
 #else
-# define OPT_INC_P 0
 # define xargs_ask_confirmation() 1
 #endif /* CONFIG_FEATURE_XARGS_SUPPORT_CONFIRMATION */
 
-#ifdef CONFIG_FEATURE_XARGS_SUPPORT_TERMOPT
-# define OPT_INC_X 1
-#else
-# define OPT_INC_X 0
-#endif
-
 #ifdef CONFIG_FEATURE_XARGS_SUPPORT_ZERO_TERM
 static xlist_t *process0_stdin(xlist_t * list_arg, const char *eof_str ATTRIBUTE_UNUSED,
 							   size_t mc, char *buf)
@@ -371,35 +360,37 @@ static xlist_t *process0_stdin(xlist_t * list_arg, const char *eof_str ATTRIBUTE
 	}
 	return list_arg;
 }
-
-# define READ_ARGS(l, e, nmc, mc) (*read_args)(l, e, nmc, mc)
-# define OPT_INC_0 1    /* future use */
-#else
-# define OPT_INC_0 0    /* future use */
-# define READ_ARGS(l, e, nmc, mc) process_stdin(l, e, nmc, mc)
 #endif /* CONFIG_FEATURE_XARGS_SUPPORT_ZERO_TERM */
 
-
-#define OPT_VERBOSE     (1<<0)
-#define OPT_NO_EMPTY    (1<<1)
-#define OPT_UPTO_NUMBER (1<<2)
-#define OPT_UPTO_SIZE   (1<<3)
-#define OPT_EOF_STRING  (1<<4)
-#ifdef CONFIG_FEATURE_XARGS_SUPPORT_CONFIRMATION
-#define OPT_INTERACTIVE (1<<5)
-#else
-#define OPT_INTERACTIVE (0)     /* require for algorithm &| */
-#endif
-#define OPT_TERMINATE   (1<<(5+OPT_INC_P))
-#define OPT_ZEROTERM    (1<<(5+OPT_INC_P+OPT_INC_X))
-/* next future
-#define OPT_NEXT_OTHER  (1<<(5+OPT_INC_P+OPT_INC_X+OPT_INC_0))
-*/
+/* Correct regardless of combination of CONFIG_xxx */
+enum {
+	OPTBIT_VERBOSE = 0,
+	OPTBIT_NO_EMPTY,
+	OPTBIT_UPTO_NUMBER,
+	OPTBIT_UPTO_SIZE,
+	OPTBIT_EOF_STRING,
+	USE_FEATURE_XARGS_SUPPORT_CONFIRMATION(OPTBIT_INTERACTIVE,)
+	USE_FEATURE_XARGS_SUPPORT_TERMOPT(     OPTBIT_TERMINATE  ,)
+	USE_FEATURE_XARGS_SUPPORT_ZERO_TERM(   OPTBIT_ZEROTERM   ,)
+
+	OPT_VERBOSE     = 1<<OPTBIT_VERBOSE    ,
+	OPT_NO_EMPTY    = 1<<OPTBIT_NO_EMPTY   ,
+	OPT_UPTO_NUMBER = 1<<OPTBIT_UPTO_NUMBER,
+	OPT_UPTO_SIZE   = 1<<OPTBIT_UPTO_SIZE  ,
+	OPT_EOF_STRING  = 1<<OPTBIT_EOF_STRING ,
+	OPT_INTERACTIVE = USE_FEATURE_XARGS_SUPPORT_CONFIRMATION((1<<OPTBIT_INTERACTIVE)) + 0,
+	OPT_TERMINATE   = USE_FEATURE_XARGS_SUPPORT_TERMOPT(     (1<<OPTBIT_TERMINATE  )) + 0,
+	OPT_ZEROTERM    = USE_FEATURE_XARGS_SUPPORT_ZERO_TERM(   (1<<OPTBIT_ZEROTERM   )) + 0,
+};
+#define OPTION_STR "+trn:s:e::" \
+	USE_FEATURE_XARGS_SUPPORT_CONFIRMATION("p") \
+	USE_FEATURE_XARGS_SUPPORT_TERMOPT(     "x") \
+	USE_FEATURE_XARGS_SUPPORT_ZERO_TERM(   "0")
 
 int xargs_main(int argc, char **argv)
 {
 	char **args;
-	int i, a, n;
+	int i, n;
 	xlist_t *list = NULL;
 	xlist_t *cur;
 	int child_error = 0;
@@ -410,42 +401,33 @@ int xargs_main(int argc, char **argv)
 	const char *eof_str = "_";
 	unsigned long opt;
 	size_t n_max_chars;
-
-#ifdef CONFIG_FEATURE_XARGS_SUPPORT_ZERO_TERM
-	xlist_t *(*read_args) (xlist_t *, const char *, size_t, char *) = process_stdin;
+#if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
+	xlist_t* (*read_args)(xlist_t*, const char*, size_t, char*) = process_stdin;
+#else
+#define read_args process_stdin
 #endif
 
-#ifdef CONFIG_FEATURE_XARGS_SUPPORT_CONFIRMATION
-	bb_opt_complementally = "pt";
-#endif
+	opt = bb_getopt_ulflags(argc, argv, OPTION_STR, &max_args, &max_chars, &eof_str);
 
-	opt = bb_getopt_ulflags(argc, argv, "+trn:s:e::"
-#ifdef CONFIG_FEATURE_XARGS_SUPPORT_CONFIRMATION
-	"p"
-#endif
-#ifdef CONFIG_FEATURE_XARGS_SUPPORT_TERMOPT
-	"x"
-#endif
-#ifdef CONFIG_FEATURE_XARGS_SUPPORT_ZERO_TERM
-	"0"
-#endif
-	,&max_args, &max_chars, &eof_str);
+	if (opt & OPT_ZEROTERM)
+		USE_FEATURE_XARGS_SUPPORT_ZERO_TERM(read_args = process0_stdin);
 
-	a = argc - optind;
+	argc -= optind;
 	argv += optind;
-	if (a == 0) {
+	if (!argc) {
 		/* default behavior is to echo all the filenames */
 		*argv = "echo";
-		a++;
+		argc++;
 	}
 
 	orig_arg_max = ARG_MAX;
 	if (orig_arg_max == -1)
 		orig_arg_max = LONG_MAX;
-	orig_arg_max -= 2048;   /* POSIX.2 requires subtracting 2048.  */
-	if ((opt & OPT_UPTO_SIZE)) {
+	orig_arg_max -= 2048;   /* POSIX.2 requires subtracting 2048 */
+
+	if (opt & OPT_UPTO_SIZE) {
 		n_max_chars = bb_xgetularg10_bnd(max_chars, 1, orig_arg_max);
-		for (i = 0; i < a; i++) {
+		for (i = 0; i < argc; i++) {
 			n_chars += strlen(*argv) + 1;
 		}
 		if (n_max_chars < n_chars) {
@@ -463,19 +445,14 @@ int xargs_main(int argc, char **argv)
 	}
 	max_chars = xmalloc(n_max_chars);
 
-	if ((opt & OPT_UPTO_NUMBER)) {
+	if (opt & OPT_UPTO_NUMBER) {
 		n_max_arg = bb_xgetularg10_bnd(max_args, 1, INT_MAX);
 	} else {
 		n_max_arg = n_max_chars;
 	}
 
-#ifdef CONFIG_FEATURE_XARGS_SUPPORT_ZERO_TERM
-	if (opt & OPT_ZEROTERM)
-		read_args = process0_stdin;
-#endif
-
-	while ((list = READ_ARGS(list, eof_str, n_max_chars, max_chars)) != NULL ||
-		(opt & OPT_NO_EMPTY) == 0)
+	while ((list = read_args(list, eof_str, n_max_chars, max_chars)) != NULL ||
+		!(opt & OPT_NO_EMPTY))
 	{
 		opt |= OPT_NO_EMPTY;
 		n = 0;
@@ -501,13 +478,13 @@ int xargs_main(int argc, char **argv)
 		}
 #endif /* CONFIG_FEATURE_XARGS_SUPPORT_TERMOPT */
 
-		/* allocating pointers for execvp:
-		   a*arg, n*arg from stdin, NULL */
-		args = xzalloc((n + a + 1) * sizeof(char *));
+		/* allocate pointers for execvp:
+		   argc*arg, n*arg from stdin, NULL */
+		args = xzalloc((n + argc + 1) * sizeof(char *));
 
-		/* Store the command to be executed
+		/* store the command to be executed
 		   (taken from the command line) */
-		for (i = 0; i < a; i++)
+		for (i = 0; i < argc; i++)
 			args[i] = argv[i];
 		/* (taken from stdin) */
 		for (cur = list; n; cur = cur->link) {
@@ -515,21 +492,21 @@ int xargs_main(int argc, char **argv)
 			n--;
 		}
 
-		if ((opt & (OPT_INTERACTIVE | OPT_VERBOSE))) {
+		if (opt & (OPT_INTERACTIVE | OPT_VERBOSE)) {
 			for (i = 0; args[i]; i++) {
 				if (i)
 					fputc(' ', stderr);
 				fputs(args[i], stderr);
 			}
-			if ((opt & OPT_INTERACTIVE) == 0)
+			if (!(opt & OPT_INTERACTIVE))
 				fputc('\n', stderr);
 		}
-		if ((opt & OPT_INTERACTIVE) == 0 || xargs_ask_confirmation() != 0) {
+		if (!(opt & OPT_INTERACTIVE) || xargs_ask_confirmation()) {
 			child_error = xargs_exec(args);
 		}
 
 		/* clean up */
-		for (i = a; args[i]; i++) {
+		for (i = argc; args[i]; i++) {
 			cur = list;
 			list = list->link;
 			free(cur);
@@ -539,9 +516,7 @@ int xargs_main(int argc, char **argv)
 			break;
 		}
 	}
-#ifdef CONFIG_FEATURE_CLEAN_UP
-	free(max_chars);
-#endif
+	if (ENABLE_FEATURE_CLEAN_UP) free(max_chars);
 	return child_error;
 }