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tr: better comments, small code shrink

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function                                             old     new   delta
expand                                              2232    2230      -2
tr_main                                              677     655     -22
This commit is contained in:
Denis Vlasenko 2007-11-13 22:22:29 +00:00
parent a89d50fb9a
commit 3d461676a9
1 changed files with 60 additions and 47 deletions
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107
coreutils/tr.c
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@ -42,19 +42,46 @@ static void map(char *pvector,
}
/* supported constructs:
* Ranges, e.g., [0-9] ==> 0123456789
* Escapes, e.g., \a ==> Control-G
* Character classes, e.g. [:upper:] ==> A ... Z
* Ranges, e.g., 0-9 ==> 0123456789
* Ranges, e.g., [0-9] ==> 0123456789
* Escapes, e.g., \a ==> Control-G
* Character classes, e.g. [:upper:] ==> A...Z
* Equiv classess, e.g. [=A=] ==> A (hmmmmmmm?)
*/
static unsigned int expand(const char *arg, char *buffer)
{
char *buffer_start = buffer;
unsigned i; /* XXX: FIXME: use unsigned char? */
unsigned i; /* can't be unsigned char: must be able to hold 256 */
unsigned char ac;
while (*arg) {
if (*arg == '\\') {
arg++;
*buffer++ = bb_process_escape_sequence(&arg);
continue;
}
if (arg[1] == '-') { /* "0-9..." */
ac = arg[2];
if (ac == '\0') { /* "0-": copy verbatim */
*buffer++ = *arg++; /* copy '0' */
continue; /* next iter will copy '-' and stop */
}
i = *arg;
while (i <= ac) /* ok: i is unsigned _int_ */
*buffer++ = i++;
arg += 3; /* skip 0-9 */
continue;
}
if (*arg == '[') { /* "[xyz..." */
arg++;
i = *arg++;
/* "[xyz...", i=x, arg points to y */
if (ENABLE_FEATURE_TR_CLASSES && i == ':') {
#define CLO ":]\0"
static const char classes[] ALIGN1 =
"alpha"CLO "alnum"CLO "digit"CLO "lower"CLO "upper"CLO "space"CLO
"blank"CLO "punct"CLO "cntrl"CLO;
static const char classes[] ALIGN1 =
"alpha"CLO "alnum"CLO "digit"CLO
"lower"CLO "upper"CLO "space"CLO
"blank"CLO "punct"CLO "cntrl"CLO;
#define CLASS_invalid 0 /* we increment the retval */
#define CLASS_alpha 1
#define CLASS_alnum 2
@ -68,27 +95,9 @@ static unsigned int expand(const char *arg, char *buffer)
//#define CLASS_xdigit 10
//#define CLASS_graph 11
//#define CLASS_print 12
while (*arg) {
if (*arg == '\\') {
arg++;
*buffer++ = bb_process_escape_sequence(&arg);
} else if (*(arg+1) == '-') {
ac = *(arg+2);
if (ac == 0) {
*buffer++ = *arg++;
continue;
}
i = *arg;
while (i <= ac)
*buffer++ = i++;
arg += 3; /* Skip the assumed a-z */
} else if (*arg == '[') {
arg++;
i = *arg++;
if (ENABLE_FEATURE_TR_CLASSES && i == ':') {
smalluint j;
{ /* not really pretty.. */
char *tmp = xstrndup(arg, 7); // warning: xdigit needs 8, not 7
char *tmp = xstrndup(arg, 7); // warning: xdigit would need 8, not 7
j = index_in_strings(classes, tmp) + 1;
free(tmp);
}
@ -115,10 +124,9 @@ static unsigned int expand(const char *arg, char *buffer)
*buffer++ = ' ';
}
if (j == CLASS_punct || j == CLASS_cntrl) {
for (i = 0; i <= ASCII; i++)
if ((j == CLASS_punct &&
isprint(i) && (!isalnum(i)) && (!isspace(i))) ||
(j == CLASS_cntrl && iscntrl(i)))
for (i = '\0'; i <= ASCII; i++)
if ((j == CLASS_punct && isprint(i) && !isalnum(i) && !isspace(i))
|| (j == CLASS_cntrl && iscntrl(i)))
*buffer++ = i;
}
if (j == CLASS_invalid) {
@ -128,22 +136,26 @@ static unsigned int expand(const char *arg, char *buffer)
}
break;
}
if (ENABLE_FEATURE_TR_EQUIV && i == '=') {
*buffer++ = *arg;
arg += 3; /* Skip the closing =] */
/* "[xyz...", i=x, arg points to y */
if (ENABLE_FEATURE_TR_EQUIV && i == '=') { /* [=CHAR=] */
*buffer++ = *arg; /* copy CHAR */
arg += 3; /* skip CHAR=] */
continue;
}
if (*arg++ != '-') {
if (*arg != '-') { /* not [x-...] - copy verbatim */
*buffer++ = '[';
arg -= 2;
continue;
arg--; /* points to x */
continue; /* copy all, including eventual ']' */
}
/* [x-y...] */
arg++;
ac = *arg++;
while (i <= ac)
*buffer++ = i++;
arg++; /* Skip the assumed ']' */
} else
*buffer++ = *arg++;
arg++; /* skip the assumed ']' */
continue;
}
*buffer++ = *arg++;
}
return (buffer - buffer_start);
}
@ -154,7 +166,7 @@ static int complement(char *buffer, int buffer_len)
char conv[ASCII + 2];
ix = 0;
for (i = 0; i <= ASCII; i++) {
for (i = '\0'; i <= ASCII; i++) {
for (j = 0; j < buffer_len; j++)
if (buffer[j] == i)
break;
@ -174,7 +186,9 @@ int tr_main(int argc, char **argv)
int i;
smalluint flags = 0;
ssize_t read_chars = 0;
size_t in_index = 0, out_index = 0, c, coded, last = -1;
size_t in_index = 0, out_index = 0;
unsigned last = UCHAR_MAX + 1; /* not equal to any char */
unsigned char coded, c;
RESERVE_CONFIG_UBUFFER(output, BUFSIZ);
RESERVE_CONFIG_BUFFER(vector, ASCII+1);
RESERVE_CONFIG_BUFFER(invec, ASCII+1);
@ -203,8 +217,8 @@ int tr_main(int argc, char **argv)
input_length = expand(argv[idx++], tr_buf);
if (flags & TR_OPT_complement)
input_length = complement(tr_buf, input_length);
if (argv[idx] != NULL) {
if (*argv[idx] == '\0')
if (argv[idx]) {
if (argv[idx][0] == '\0')
bb_error_msg_and_die("STRING2 cannot be empty");
output_length = expand(argv[idx], output);
map(vector, tr_buf, input_length, output, output_length);
@ -222,9 +236,8 @@ int tr_main(int argc, char **argv)
xwrite(STDOUT_FILENO, (char *)output, out_index);
out_index = 0;
}
read_chars = read(STDIN_FILENO, tr_buf, BUFSIZ);
read_chars = safe_read(STDIN_FILENO, tr_buf, BUFSIZ);
if (read_chars <= 0) {
xwrite(STDOUT_FILENO, (char *)output, out_index);
if (read_chars < 0)
bb_perror_msg_and_die(bb_msg_read_error);
exit(EXIT_SUCCESS);
@ -235,8 +248,8 @@ int tr_main(int argc, char **argv)
coded = vector[c];
if ((flags & TR_OPT_delete) && invec[c])
continue;
if ((flags & TR_OPT_squeeze_reps) && last == coded &&
(invec[c] || outvec[coded]))
if ((flags & TR_OPT_squeeze_reps) && last == coded
&& (invec[c] || outvec[coded]))
continue;
output[out_index++] = last = coded;
}