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xargs: code shrink -15 bytes

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Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2010-06-13 03:43:43 +02:00
parent d2d327db6d
commit d5fa1a0f49
2 changed files with 80 additions and 81 deletions
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148
findutils/xargs.c
View File

@ -122,11 +122,10 @@ typedef struct xlist_t {
char xstr[1]; char xstr[1];
} xlist_t; } xlist_t;
static smallint eof_stdin_detected; /* In POSIX/C locale isspace is only these chars: "\t\n\v\f\r" and space.
* "\t\n\v\f\r" happen to have ASCII codes 9,10,11,12,13.
#define ISBLANK(c) ((c) == ' ' || (c) == '\t') */
#define ISSPACE(c) (ISBLANK(c) || (c) == '\n' || (c) == '\r' \ #define ISSPACE(a) ({ unsigned char xargs__isspace = (a) - 9; xargs__isspace == (' ' - 9) || xargs__isspace <= (13 - 9); })
|| (c) == '\f' || (c) == '\v')
#if ENABLE_FEATURE_XARGS_SUPPORT_QUOTES #if ENABLE_FEATURE_XARGS_SUPPORT_QUOTES
static xlist_t* process_stdin(xlist_t *list_arg, static xlist_t* process_stdin(xlist_t *list_arg,
@ -136,39 +135,36 @@ static xlist_t *process_stdin(xlist_t *list_arg,
#define QUOTE 1 #define QUOTE 1
#define BACKSLASH 2 #define BACKSLASH 2
#define SPACE 4 #define SPACE 4
char *s = NULL; /* start of the word */
char *s = NULL; /* start word */ char *p = NULL; /* pointer to end of the word */
char *p = NULL; /* pointer to end word */
char q = '\0'; /* quote char */ char q = '\0'; /* quote char */
char state = NORM; char state = NORM;
char eof_str_detected = 0; char eof_str_detected = 0;
size_t line_l = 0; /* size loaded args line */ size_t line_l = 0; /* size of loaded args */
int c; /* current char */
xlist_t *cur; xlist_t *cur;
xlist_t *prev; xlist_t *prev;
prev = cur = list_arg; prev = cur = list_arg;
while (1) { while (cur) {
if (!cur) break;
prev = cur; prev = cur;
line_l += cur->length; line_l += cur->length;
cur = cur->link; cur = cur->link;
} }
while (!eof_stdin_detected) { while (1) {
c = getchar(); int c = getchar();
if (c == EOF) { if (c == EOF) {
eof_stdin_detected = 1;
if (s) if (s)
goto unexpected_eof; goto unexpected_eof;
break; break;
} }
if (eof_str_detected) if (eof_str_detected) /* skip till EOF */
continue; continue;
if (state == BACKSLASH) { if (state == BACKSLASH) {
state = NORM; state = NORM;
goto set; goto set;
} else if (state == QUOTE) { }
if (state == QUOTE) {
if (c != q) if (c != q)
goto set; goto set;
q = '\0'; q = '\0';
@ -202,7 +198,7 @@ static xlist_t *process_stdin(xlist_t *list_arg,
bb_error_msg_and_die("unmatched %s quote", bb_error_msg_and_die("unmatched %s quote",
q == '\'' ? "single" : "double"); q == '\'' ? "single" : "double");
} }
/* word loaded */ /* A full word is loaded */
if (eof_str) { if (eof_str) {
eof_str_detected = (strcmp(s, eof_str) == 0); eof_str_detected = (strcmp(s, eof_str) == 0);
} }
@ -220,11 +216,9 @@ static xlist_t *process_stdin(xlist_t *list_arg,
} }
prev = cur; prev = cur;
line_l += length; line_l += length;
if (line_l > mc) { if (line_l > mc) /* limit stop memory usage */
/* stop memory usage :-) */
break; break;
} }
}
s = NULL; s = NULL;
state = NORM; state = NORM;
} }
@ -236,30 +230,29 @@ static xlist_t *process_stdin(xlist_t *list_arg,
static xlist_t* process_stdin(xlist_t *list_arg, static xlist_t* process_stdin(xlist_t *list_arg,
const char *eof_str, size_t mc, char *buf) const char *eof_str, size_t mc, char *buf)
{ {
int c; /* current char */
char eof_str_detected = 0; char eof_str_detected = 0;
char *s = NULL; /* start word */ char *s = NULL; /* start of the word */
char *p = NULL; /* pointer to end word */ char *p = NULL; /* pointer to end of the word */
size_t line_l = 0; /* size loaded args line */ size_t line_l = 0; /* size of loaded args */
xlist_t *cur; xlist_t *cur;
xlist_t *prev; xlist_t *prev;
prev = cur = list_arg; prev = cur = list_arg;
while (1) { while (cur) {
if (!cur) break;
prev = cur; prev = cur;
line_l += cur->length; line_l += cur->length;
cur = cur->link; cur = cur->link;
} }
while (!eof_stdin_detected) { while (1) {
c = getchar(); int c = getchar();
if (c == EOF) { if (c == EOF) {
eof_stdin_detected = 1; if (s == NULL)
break;
} }
if (eof_str_detected) if (eof_str_detected) { /* skip till EOF */
continue; continue;
}
if (c == EOF || ISSPACE(c)) { if (c == EOF || ISSPACE(c)) {
if (s == NULL) if (s == NULL)
continue; continue;
@ -271,7 +264,7 @@ static xlist_t *process_stdin(xlist_t *list_arg,
bb_error_msg_and_die("argument line too long"); bb_error_msg_and_die("argument line too long");
*p++ = (c == EOF ? '\0' : c); *p++ = (c == EOF ? '\0' : c);
if (c == EOF) { /* word's delimiter or EOF detected */ if (c == EOF) { /* word's delimiter or EOF detected */
/* word loaded */ /* A full word is loaded */
if (eof_str) { if (eof_str) {
eof_str_detected = (strcmp(s, eof_str) == 0); eof_str_detected = (strcmp(s, eof_str) == 0);
} }
@ -289,14 +282,12 @@ static xlist_t *process_stdin(xlist_t *list_arg,
} }
prev = cur; prev = cur;
line_l += length; line_l += length;
if (line_l > mc) { if (line_l > mc) /* limit stop memory usage */
/* stop memory usage :-) */
break; break;
} }
s = NULL; s = NULL;
} }
} }
}
return list_arg; return list_arg;
} }
#endif /* FEATURE_XARGS_SUPPORT_QUOTES */ #endif /* FEATURE_XARGS_SUPPORT_QUOTES */
@ -328,25 +319,22 @@ static int xargs_ask_confirmation(void)
static xlist_t* process0_stdin(xlist_t *list_arg, static xlist_t* process0_stdin(xlist_t *list_arg,
const char *eof_str UNUSED_PARAM, size_t mc, char *buf) const char *eof_str UNUSED_PARAM, size_t mc, char *buf)
{ {
int c; /* current char */ char *s = NULL; /* start of the word */
char *s = NULL; /* start word */ char *p = NULL; /* pointer to end of the word */
char *p = NULL; /* pointer to end word */ size_t line_l = 0; /* size of loaded args */
size_t line_l = 0; /* size loaded args line */
xlist_t *cur; xlist_t *cur;
xlist_t *prev; xlist_t *prev;
prev = cur = list_arg; prev = cur = list_arg;
while (1) { while (cur) {
if (!cur) break;
prev = cur; prev = cur;
line_l += cur->length; line_l += cur->length;
cur = cur->link; cur = cur->link;
} }
while (!eof_stdin_detected) { while (1) {
c = getchar(); int c = getchar();
if (c == EOF) { if (c == EOF) {
eof_stdin_detected = 1;
if (s == NULL) if (s == NULL)
break; break;
c = '\0'; c = '\0';
@ -357,7 +345,7 @@ static xlist_t *process0_stdin(xlist_t *list_arg,
bb_error_msg_and_die("argument line too long"); bb_error_msg_and_die("argument line too long");
*p++ = c; *p++ = c;
if (c == '\0') { /* word's delimiter or EOF detected */ if (c == '\0') { /* word's delimiter or EOF detected */
/* word loaded */ /* A full word is loaded */
size_t length = (p - buf); size_t length = (p - buf);
/* Dont xzalloc - it can be quite big */ /* Dont xzalloc - it can be quite big */
cur = xmalloc(offsetof(xlist_t, xstr) + length); cur = xmalloc(offsetof(xlist_t, xstr) + length);
@ -371,10 +359,8 @@ static xlist_t *process0_stdin(xlist_t *list_arg,
} }
prev = cur; prev = cur;
line_l += length; line_l += length;
if (line_l > mc) { if (line_l > mc) /* limit stop memory usage */
/* stop memory usage :-) */
break; break;
}
s = NULL; s = NULL;
} }
} }
@ -412,12 +398,11 @@ enum {
int xargs_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int xargs_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int xargs_main(int argc, char **argv) int xargs_main(int argc, char **argv)
{ {
char **args;
int i, n;
xlist_t *list = NULL; xlist_t *list = NULL;
xlist_t *cur;
int child_error = 0; int child_error = 0;
char *max_args, *max_chars; char *max_args;
char *max_chars;
char *buf;
int n_max_arg; int n_max_arg;
const char *eof_str = NULL; const char *eof_str = NULL;
unsigned opt; unsigned opt;
@ -441,15 +426,12 @@ int xargs_main(int argc, char **argv)
argv += optind; argv += optind;
argc -= optind; argc -= optind;
if (!argc) { if (!argv[0]) {
/* default behavior is to echo all the filenames */ /* default behavior is to echo all the filenames */
*argv = (char*)"echo"; *--argv = (char*)"echo";
argc++; argc++;
} }
n_max_chars = ARG_MAX; /* might be calling sysconf(_SC_ARG_MAX) */
if (n_max_chars < 4*1024); /* paranoia */
n_max_chars = LONG_MAX;
/* The Open Group Base Specifications Issue 6: /* The Open Group Base Specifications Issue 6:
* "The xargs utility shall limit the command line length such that * "The xargs utility shall limit the command line length such that
* when the command line is invoked, the combined argument * when the command line is invoked, the combined argument
@ -457,27 +439,32 @@ int xargs_main(int argc, char **argv)
* in the System Interfaces volume of IEEE Std 1003.1-2001) * in the System Interfaces volume of IEEE Std 1003.1-2001)
* shall not exceed {ARG_MAX}-2048 bytes". * shall not exceed {ARG_MAX}-2048 bytes".
*/ */
n_max_chars = ARG_MAX; /* might be calling sysconf(_SC_ARG_MAX) */
if (n_max_chars < 4*1024); /* paranoia */
n_max_chars = 4*1024;
n_max_chars -= 2048; n_max_chars -= 2048;
/* Sanity check for systems with huge ARG_MAX defines (e.g., Suns which /* Sanity check for systems with huge ARG_MAX defines (e.g., Suns which
* have it at 1 meg). Things will work fine with a large ARG_MAX but it * have it at 1 meg). Things will work fine with a large ARG_MAX
* will probably hurt the system more than it needs to; an array of this * but it will probably hurt the system more than it needs to;
* size is allocated. * an array of this size is allocated.
*/ */
if (n_max_chars > 20 * 1024) if (n_max_chars > 20 * 1024)
n_max_chars = 20 * 1024; n_max_chars = 20 * 1024;
if (opt & OPT_UPTO_SIZE) { if (opt & OPT_UPTO_SIZE) {
int i;
size_t n_chars = 0; size_t n_chars = 0;
n_max_chars = xatoul_range(max_chars, 1, n_max_chars); n_max_chars = xatoul_range(max_chars, 1, n_max_chars);
for (i = 0; i < argc; i++) { for (i = 0; argv[i]; i++) {
n_chars += strlen(*argv) + 1; n_chars += strlen(argv[i]) + 1;
}
if (n_max_chars <= n_chars) {
bb_error_msg_and_die("can't fit single argument within argument list size limit");
} }
n_max_chars -= n_chars; n_max_chars -= n_chars;
if ((ssize_t)n_max_chars <= 0) {
bb_error_msg_and_die("can't fit single argument within argument list size limit");
} }
max_chars = xmalloc(n_max_chars); }
buf = xmalloc(n_max_chars);
if (opt & OPT_UPTO_NUMBER) { if (opt & OPT_UPTO_NUMBER) {
n_max_arg = xatoul_range(max_args, 1, INT_MAX); n_max_arg = xatoul_range(max_args, 1, INT_MAX);
@ -485,10 +472,14 @@ int xargs_main(int argc, char **argv)
n_max_arg = n_max_chars; n_max_arg = n_max_chars;
} }
while ((list = read_args(list, eof_str, n_max_chars, max_chars)) != NULL || while ((list = read_args(list, eof_str, n_max_chars, buf)) != NULL
!(opt & OPT_NO_EMPTY)) || !(opt & OPT_NO_EMPTY)
{ ) {
char **args;
xlist_t *cur;
int i, n;
size_t n_chars = 0; size_t n_chars = 0;
opt |= OPT_NO_EMPTY; opt |= OPT_NO_EMPTY;
n = 0; n = 0;
#if ENABLE_FEATURE_XARGS_SUPPORT_TERMOPT #if ENABLE_FEATURE_XARGS_SUPPORT_TERMOPT
@ -510,15 +501,14 @@ int xargs_main(int argc, char **argv)
break; break;
} }
} }
#endif /* FEATURE_XARGS_SUPPORT_TERMOPT */ #endif
/* allocate pointers for execvp: /* allocate pointers for execvp */
argc*arg, n*arg from stdin, NULL */ args = xzalloc(sizeof(args[0]) * (argc + n + 1));
args = xzalloc((n + argc + 1) * sizeof(char *));
/* store the command to be executed /* store the command to be executed
(taken from the command line) */ * (taken from the command line) */
for (i = 0; i < argc; i++) for (i = 0; argv[i]; i++)
args[i] = argv[i]; args[i] = argv[i];
/* (taken from stdin) */ /* (taken from stdin) */
for (cur = list; n; cur = cur->link) { for (cur = list; n; cur = cur->link) {
@ -535,6 +525,7 @@ int xargs_main(int argc, char **argv)
if (!(opt & OPT_INTERACTIVE)) if (!(opt & OPT_INTERACTIVE))
bb_putchar_stderr('\n'); bb_putchar_stderr('\n');
} }
if (!(opt & OPT_INTERACTIVE) || xargs_ask_confirmation()) { if (!(opt & OPT_INTERACTIVE) || xargs_ask_confirmation()) {
child_error = xargs_exec(args); child_error = xargs_exec(args);
} }
@ -546,12 +537,15 @@ int xargs_main(int argc, char **argv)
free(cur); free(cur);
} }
free(args); free(args);
if (child_error > 0 && child_error != 123) { if (child_error > 0 && child_error != 123) {
break; break;
} }
} /* while */ } /* while */
if (ENABLE_FEATURE_CLEAN_UP) if (ENABLE_FEATURE_CLEAN_UP)
free(max_chars); free(buf);
return child_error; return child_error;
} }

5
testsuite/xargs.tests
View File

@ -26,4 +26,9 @@ testing "xargs does not stop on underscore ('new' GNU behavior)" \
"a _ b\n" \ "a _ b\n" \
"" "a\n_\nb\n" "" "a\n_\nb\n"
testing "xargs -s7 can take one-char input" \
"xargs -s7" \
"a\n" \
"" "a\n"
exit $FAILCOUNT exit $FAILCOUNT