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authorGravatar Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>2015-02-16 17:12:04 +0100
committerGravatar Denys Vlasenko <vda.linux@googlemail.com>2015-02-16 17:12:04 +0100
commit70e30e8eec7f202cb584449e4c7a9176d57d980d (patch)
treef502c4819933beeb15d1ad50c0f335318495fa25 /miscutils/dc.c
parent8e92df15b512d108901ce1762e917518553a8aaf (diff)
downloadbusybox-70e30e8eec7f202cb584449e4c7a9176d57d980d.tar.gz
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dc: tweak parsing
https://bugs.debian.org/538685 dc requires whitespace between language elements. We were requiring 1 2 + p instead of the abbreviated 1 2+p (for example). function old new delta stack_machine 97 126 +29 dc_main 117 79 -38 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 1/1 up/down: 29/-38) Total: -9 bytes Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'miscutils/dc.c')
-rw-r--r--miscutils/dc.c57
1 files changed, 27 insertions, 30 deletions
diff --git a/miscutils/dc.c b/miscutils/dc.c
index 6bcfbe249..a7bd360d2 100644
--- a/miscutils/dc.c
+++ b/miscutils/dc.c
@@ -196,14 +196,6 @@ struct op {
};
static const struct op operators[] = {
- {"+", add},
- {"add", add},
- {"-", sub},
- {"sub", sub},
- {"*", mul},
- {"mul", mul},
- {"/", divide},
- {"div", divide},
#if ENABLE_FEATURE_DC_LIBM
{"**", power},
{"exp", power},
@@ -216,28 +208,47 @@ static const struct op operators[] = {
{"not", not},
{"eor", eor},
{"xor", eor},
+ {"+", add},
+ {"add", add},
+ {"-", sub},
+ {"sub", sub},
+ {"*", mul},
+ {"mul", mul},
+ {"/", divide},
+ {"div", divide},
{"p", print_no_pop},
{"f", print_stack_no_pop},
{"o", set_output_base},
};
+/* Feed the stack machine */
static void stack_machine(const char *argument)
{
char *end;
- double d;
+ double number;
const struct op *o;
- d = strtod(argument, &end);
- if (end != argument && *end == '\0') {
- push(d);
- return;
+ next:
+ number = strtod(argument, &end);
+ if (end != argument) {
+ argument = end;
+ push(number);
+ goto next;
}
+ /* We might have matched a digit, eventually advance the argument */
+ argument = skip_whitespace(argument);
+
+ if (*argument == '\0')
+ return;
+
o = operators;
do {
- if (strcmp(o->name, argument) == 0) {
+ const size_t name_len = strlen(o->name);
+ if (strncmp(o->name, argument, name_len) == 0) {
+ argument += name_len;
o->function();
- return;
+ goto next;
}
o++;
} while (o != operators + ARRAY_SIZE(operators));
@@ -254,25 +265,11 @@ int dc_main(int argc UNUSED_PARAM, char **argv)
if (!argv[0]) {
/* take stuff from stdin if no args are given */
char *line;
- char *cursor;
- char *token;
while ((line = xmalloc_fgetline(stdin)) != NULL) {
- cursor = line;
- while (1) {
- token = skip_whitespace(cursor);
- if (*token == '\0')
- break;
- cursor = skip_non_whitespace(token);
- if (*cursor != '\0')
- *cursor++ = '\0';
- stack_machine(token);
- }
+ stack_machine(line);
free(line);
}
} else {
- // why? it breaks "dc -2 2 + p"
- //if (argv[0][0] == '-')
- // bb_show_usage();
do {
stack_machine(*argv);
} while (*++argv);