xargs: simplify option parsing

1 files changed, 91 insertions, 116 deletions

diff --git a/findutils/xargs.c b/findutils/xargs.c
index d067a3f48..b6a154f15 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;
 }