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authorDenis Vlasenko2007-11-13 22:22:29 +0000
committerDenis Vlasenko2007-11-13 22:22:29 +0000
commit3d461676a90eecf584dc07317cdb52eba96aa2d9 (patch)
tree7e2a706b4d19a27312be5f036dd557ea518a7790 /coreutils
parenta89d50fb9addfe0060f697a7e1d31a7b3010b2bb (diff)
downloadbusybox-3d461676a90eecf584dc07317cdb52eba96aa2d9.zip
busybox-3d461676a90eecf584dc07317cdb52eba96aa2d9.tar.gz
tr: better comments, small code shrink
function old new delta expand 2232 2230 -2 tr_main 677 655 -22
Diffstat (limited to 'coreutils')
-rw-r--r--coreutils/tr.c107
1 files changed, 60 insertions, 47 deletions
diff --git a/coreutils/tr.c b/coreutils/tr.c
index e60e08b..f6f458b 100644
--- a/coreutils/tr.c
+++ b/coreutils/tr.c
@@ -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;
}