xargs: code shrink -15 bytes

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

View File

@ -122,53 +122,49 @@ typedef struct xlist_t {
char xstr[1];
} xlist_t;
static smallint eof_stdin_detected;
#define ISBLANK(c) ((c) == ' ' || (c) == '\t')
#define ISSPACE(c) (ISBLANK(c) || (c) == '\n' || (c) == '\r' \
|| (c) == '\f' || (c) == '\v')
/* 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 ISSPACE(a) ({ unsigned char xargs__isspace = (a) - 9; xargs__isspace == (' ' - 9) || xargs__isspace <= (13 - 9); })
#if ENABLE_FEATURE_XARGS_SUPPORT_QUOTES
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)
{
#define NORM 0
#define QUOTE 1
#define BACKSLASH 2
#define SPACE 4
char *s = NULL; /* start word */
char *p = NULL; /* pointer to end word */
char *s = NULL; /* start of the word */
char *p = NULL; /* pointer to end of the word */
char q = '\0'; /* quote char */
char state = NORM;
char eof_str_detected = 0;
size_t line_l = 0; /* size loaded args line */
int c; /* current char */
size_t line_l = 0; /* size of loaded args */
xlist_t *cur;
xlist_t *prev;
prev = cur = list_arg;
while (1) {
if (!cur) break;
while (cur) {
prev = cur;
line_l += cur->length;
cur = cur->link;
}
while (!eof_stdin_detected) {
c = getchar();
while (1) {
int c = getchar();
if (c == EOF) {
eof_stdin_detected = 1;
if (s)
goto unexpected_eof;
break;
}
if (eof_str_detected)
if (eof_str_detected) /* skip till EOF */
continue;
if (state == BACKSLASH) {
state = NORM;
goto set;
} else if (state == QUOTE) {
}
if (state == QUOTE) {
if (c != q)
goto set;
q = '\0';
@ -202,7 +198,7 @@ static xlist_t *process_stdin(xlist_t *list_arg,
bb_error_msg_and_die("unmatched %s quote",
q == '\'' ? "single" : "double");
}
/* word loaded */
/* A full word is loaded */
if (eof_str) {
eof_str_detected = (strcmp(s, eof_str) == 0);
}
@ -220,10 +216,8 @@ static xlist_t *process_stdin(xlist_t *list_arg,
}
prev = cur;
line_l += length;
if (line_l > mc) {
/* stop memory usage :-) */
if (line_l > mc) /* limit stop memory usage */
break;
}
}
s = NULL;
state = NORM;
@ -233,33 +227,32 @@ static xlist_t *process_stdin(xlist_t *list_arg,
}
#else
/* The variant does not support single quotes, double quotes or backslash */
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)
{
int c; /* current char */
char eof_str_detected = 0;
char *s = NULL; /* start word */
char *p = NULL; /* pointer to end word */
size_t line_l = 0; /* size loaded args line */
char *s = NULL; /* start of the word */
char *p = NULL; /* pointer to end of the word */
size_t line_l = 0; /* size of loaded args */
xlist_t *cur;
xlist_t *prev;
prev = cur = list_arg;
while (1) {
if (!cur) break;
while (cur) {
prev = cur;
line_l += cur->length;
cur = cur->link;
}
while (!eof_stdin_detected) {
c = getchar();
while (1) {
int c = getchar();
if (c == EOF) {
eof_stdin_detected = 1;
if (s == NULL)
break;
}
if (eof_str_detected)
if (eof_str_detected) { /* skip till EOF */
continue;
}
if (c == EOF || ISSPACE(c)) {
if (s == NULL)
continue;
@ -271,7 +264,7 @@ static xlist_t *process_stdin(xlist_t *list_arg,
bb_error_msg_and_die("argument line too long");
*p++ = (c == EOF ? '\0' : c);
if (c == EOF) { /* word's delimiter or EOF detected */
/* word loaded */
/* A full word is loaded */
if (eof_str) {
eof_str_detected = (strcmp(s, eof_str) == 0);
}
@ -289,12 +282,10 @@ static xlist_t *process_stdin(xlist_t *list_arg,
}
prev = cur;
line_l += length;
if (line_l > mc) {
/* stop memory usage :-) */
if (line_l > mc) /* limit stop memory usage */
break;
}
s = NULL;
}
s = NULL;
}
}
return list_arg;
@ -325,28 +316,25 @@ static int xargs_ask_confirmation(void)
#endif /* FEATURE_XARGS_SUPPORT_CONFIRMATION */
#if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
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)
{
int c; /* current char */
char *s = NULL; /* start word */
char *p = NULL; /* pointer to end word */
size_t line_l = 0; /* size loaded args line */
char *s = NULL; /* start of the word */
char *p = NULL; /* pointer to end of the word */
size_t line_l = 0; /* size of loaded args */
xlist_t *cur;
xlist_t *prev;
prev = cur = list_arg;
while (1) {
if (!cur) break;
while (cur) {
prev = cur;
line_l += cur->length;
cur = cur->link;
}
while (!eof_stdin_detected) {
c = getchar();
while (1) {
int c = getchar();
if (c == EOF) {
eof_stdin_detected = 1;
if (s == NULL)
break;
c = '\0';
@ -357,7 +345,7 @@ static xlist_t *process0_stdin(xlist_t *list_arg,
bb_error_msg_and_die("argument line too long");
*p++ = c;
if (c == '\0') { /* word's delimiter or EOF detected */
/* word loaded */
/* A full word is loaded */
size_t length = (p - buf);
/* Dont xzalloc - it can be quite big */
cur = xmalloc(offsetof(xlist_t, xstr) + length);
@ -371,10 +359,8 @@ static xlist_t *process0_stdin(xlist_t *list_arg,
}
prev = cur;
line_l += length;
if (line_l > mc) {
/* stop memory usage :-) */
if (line_l > mc) /* limit stop memory usage */
break;
}
s = NULL;
}
}
@ -412,12 +398,11 @@ enum {
int xargs_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int xargs_main(int argc, char **argv)
{
char **args;
int i, n;
xlist_t *list = NULL;
xlist_t *cur;
int child_error = 0;
char *max_args, *max_chars;
char *max_args;
char *max_chars;
char *buf;
int n_max_arg;
const char *eof_str = NULL;
unsigned opt;
@ -441,15 +426,12 @@ int xargs_main(int argc, char **argv)
argv += optind;
argc -= optind;
if (!argc) {
if (!argv[0]) {
/* default behavior is to echo all the filenames */
*argv = (char*)"echo";
*--argv = (char*)"echo";
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 xargs utility shall limit the command line length such that
* 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)
* 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;
/* 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
* will probably hurt the system more than it needs to; an array of this
* size is allocated.
* have it at 1 meg). Things will work fine with a large ARG_MAX
* but it will probably hurt the system more than it needs to;
* an array of this size is allocated.
*/
if (n_max_chars > 20 * 1024)
n_max_chars = 20 * 1024;
if (opt & OPT_UPTO_SIZE) {
int i;
size_t n_chars = 0;
n_max_chars = xatoul_range(max_chars, 1, n_max_chars);
for (i = 0; i < argc; i++) {
n_chars += strlen(*argv) + 1;
}
if (n_max_chars <= n_chars) {
bb_error_msg_and_die("can't fit single argument within argument list size limit");
for (i = 0; argv[i]; i++) {
n_chars += strlen(argv[i]) + 1;
}
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) {
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;
}
while ((list = read_args(list, eof_str, n_max_chars, max_chars)) != NULL ||
!(opt & OPT_NO_EMPTY))
{
while ((list = read_args(list, eof_str, n_max_chars, buf)) != NULL
|| !(opt & OPT_NO_EMPTY)
) {
char **args;
xlist_t *cur;
int i, n;
size_t n_chars = 0;
opt |= OPT_NO_EMPTY;
n = 0;
#if ENABLE_FEATURE_XARGS_SUPPORT_TERMOPT
@ -510,15 +501,14 @@ int xargs_main(int argc, char **argv)
break;
}
}
#endif /* FEATURE_XARGS_SUPPORT_TERMOPT */
#endif
/* allocate pointers for execvp:
argc*arg, n*arg from stdin, NULL */
args = xzalloc((n + argc + 1) * sizeof(char *));
/* allocate pointers for execvp */
args = xzalloc(sizeof(args[0]) * (argc + n + 1));
/* store the command to be executed
(taken from the command line) */
for (i = 0; i < argc; i++)
* (taken from the command line) */
for (i = 0; argv[i]; i++)
args[i] = argv[i];
/* (taken from stdin) */
for (cur = list; n; cur = cur->link) {
@ -535,6 +525,7 @@ int xargs_main(int argc, char **argv)
if (!(opt & OPT_INTERACTIVE))
bb_putchar_stderr('\n');
}
if (!(opt & OPT_INTERACTIVE) || xargs_ask_confirmation()) {
child_error = xargs_exec(args);
}
@ -546,12 +537,15 @@ int xargs_main(int argc, char **argv)
free(cur);
}
free(args);
if (child_error > 0 && child_error != 123) {
break;
}
} /* while */
if (ENABLE_FEATURE_CLEAN_UP)
free(max_chars);
free(buf);
return child_error;
}

View File

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