busybox/coreutils/sort.c
2006-11-26 15:48:54 +00:00

358 lines
9.2 KiB
C

/* vi: set sw=4 ts=4: */
/*
* SuS3 compliant sort implementation for busybox
*
* Copyright (C) 2004 by Rob Landley <rob@landley.net>
*
* MAINTAINER: Rob Landley <rob@landley.net>
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*
* See SuS3 sort standard at:
* http://www.opengroup.org/onlinepubs/007904975/utilities/sort.html
*/
#include "busybox.h"
static int global_flags;
/*
sort [-m][-o output][-bdfinru][-t char][-k keydef]... [file...]
sort -c [-bdfinru][-t char][-k keydef][file]
*/
/* These are sort types */
#define FLAG_n 1 /* Numeric sort */
#define FLAG_g 2 /* Sort using strtod() */
#define FLAG_M 4 /* Sort date */
/* ucsz apply to root level only, not keys. b at root level implies bb */
#define FLAG_u 8 /* Unique */
#define FLAG_c 16 /* Check: no output, exit(!ordered) */
#define FLAG_s 32 /* Stable sort, no ascii fallback at end */
#define FLAG_z 64 /* Input is null terminated, not \n */
/* These can be applied to search keys, the previous four can't */
#define FLAG_b 128 /* Ignore leading blanks */
#define FLAG_r 256 /* Reverse */
#define FLAG_d 512 /* Ignore !(isalnum()|isspace()) */
#define FLAG_f 1024 /* Force uppercase */
#define FLAG_i 2048 /* Ignore !isprint() */
#define FLAG_bb 32768 /* Ignore trailing blanks */
#if ENABLE_FEATURE_SORT_BIG
static char key_separator;
static struct sort_key {
struct sort_key *next_key; /* linked list */
unsigned short range[4]; /* start word, start char, end word, end char */
int flags;
} *key_list;
static char *get_key(char *str, struct sort_key *key, int flags)
{
int start = 0, end = 0, len, i, j;
/* Special case whole string, so we don't have to make a copy */
if (key->range[0] == 1 && !key->range[1] && !key->range[2] && !key->range[3]
&& !(flags & (FLAG_b | FLAG_d | FLAG_f | FLAG_i | FLAG_bb))
) {
return str;
}
/* Find start of key on first pass, end on second pass*/
len = strlen(str);
for (j = 0; j < 2; j++) {
if (!key->range[2*j])
end = len;
/* Loop through fields */
else {
end = 0;
for (i = 1; i < key->range[2*j] + j; i++) {
/* Skip leading blanks or first separator */
if (str[end]) {
if (!key_separator)
while (isspace(str[end])) end++;
}
/* Skip body of key */
for (; str[end]; end++) {
if (key_separator) {
if (str[end] == key_separator)
break;
} else {
if (isspace(str[end]))
break;
}
}
}
}
if (!j) start = end;
}
/* Key with explicit separator starts after separator */
if (key_separator && str[start] == key_separator)
start++;
/* Strip leading whitespace if necessary */
//XXX: skip_whitespace()
if (flags & FLAG_b)
while (isspace(str[start])) start++;
/* Strip trailing whitespace if necessary */
if (flags & FLAG_bb)
while (end > start && isspace(str[end-1])) end--;
/* Handle offsets on start and end */
if (key->range[3]) {
end += key->range[3] - 1;
if (end > len) end = len;
}
if (key->range[1]) {
start += key->range[1] - 1;
if (start > len) start = len;
}
/* Make the copy */
if (end < start) end = start;
str = xstrndup(str+start, end-start);
/* Handle -d */
if (flags & FLAG_d) {
for (start = end = 0; str[end]; end++)
if (isspace(str[end]) || isalnum(str[end]))
str[start++] = str[end];
str[start] = '\0';
}
/* Handle -i */
if (flags & FLAG_i) {
for (start = end = 0; str[end]; end++)
if (isprint(str[end]))
str[start++] = str[end];
str[start] = '\0';
}
/* Handle -f */
if (flags & FLAG_f)
for (i = 0; str[i]; i++)
str[i] = toupper(str[i]);
return str;
}
static struct sort_key *add_key(void)
{
struct sort_key **pkey = &key_list;
while (*pkey)
pkey = &((*pkey)->next_key);
return *pkey = xzalloc(sizeof(struct sort_key));
}
#define GET_LINE(fp) \
((global_flags & FLAG_z) \
? bb_get_chunk_from_file(fp, NULL) \
: xmalloc_getline(fp))
#else
#define GET_LINE(fp) xmalloc_getline(fp)
#endif
/* Iterate through keys list and perform comparisons */
static int compare_keys(const void *xarg, const void *yarg)
{
int flags = global_flags, retval = 0;
char *x, *y;
#if ENABLE_FEATURE_SORT_BIG
struct sort_key *key;
for (key = key_list; !retval && key; key = key->next_key) {
flags = key->flags ? key->flags : global_flags;
/* Chop out and modify key chunks, handling -dfib */
x = get_key(*(char **)xarg, key, flags);
y = get_key(*(char **)yarg, key, flags);
#else
/* This curly bracket serves no purpose but to match the nesting
level of the for() loop we're not using */
{
x = *(char **)xarg;
y = *(char **)yarg;
#endif
/* Perform actual comparison */
switch (flags & 7) {
default:
bb_error_msg_and_die("unknown sort type");
break;
/* Ascii sort */
case 0:
retval = strcmp(x, y);
break;
#if ENABLE_FEATURE_SORT_BIG
case FLAG_g: {
char *xx, *yy;
double dx = strtod(x, &xx);
double dy = strtod(y, &yy);
/* not numbers < NaN < -infinity < numbers < +infinity) */
if (x == xx)
retval = (y == yy ? 0 : -1);
else if (y == yy)
retval = 1;
/* Check for isnan */
else if (dx != dx)
retval = (dy != dy) ? 0 : -1;
else if (dy != dy)
retval = 1;
/* Check for infinity. Could underflow, but it avoids libm. */
else if (1.0 / dx == 0.0) {
if (dx < 0)
retval = (1.0 / dy == 0.0 && dy < 0) ? 0 : -1;
else
retval = (1.0 / dy == 0.0 && dy > 0) ? 0 : 1;
} else if (1.0 / dy == 0.0)
retval = (dy < 0) ? 1 : -1;
else
retval = (dx > dy) ? 1 : ((dx < dy) ? -1 : 0);
break;
}
case FLAG_M: {
struct tm thyme;
int dx;
char *xx, *yy;
xx = strptime(x, "%b", &thyme);
dx = thyme.tm_mon;
yy = strptime(y, "%b", &thyme);
if (!xx)
retval = (!yy) ? 0 : -1;
else if (!yy)
retval = 1;
else
retval = (dx == thyme.tm_mon) ? 0 : dx - thyme.tm_mon;
break;
}
/* Full floating point version of -n */
case FLAG_n: {
double dx = atof(x);
double dy = atof(y);
retval = (dx > dy) ? 1 : ((dx < dy) ? -1 : 0);
break;
}
} /* switch */
/* Free key copies. */
if (x != *(char **)xarg) free(x);
if (y != *(char **)yarg) free(y);
/* if (retval) break; - done by for() anyway */
#else
/* Integer version of -n for tiny systems */
case FLAG_n:
retval = atoi(x) - atoi(y);
break;
} /* switch */
#endif
}
/* Perform fallback sort if necessary */
if (!retval && !(global_flags & FLAG_s))
retval = strcmp(*(char **)xarg, *(char **)yarg);
if (flags & FLAG_r) return -retval;
return retval;
}
int sort_main(int argc, char **argv)
{
FILE *fp, *outfile = NULL;
int linecount = 0, i, flag;
char *line, **lines = NULL, *optlist = "ngMucszbrdfimS:T:o:k:t:";
int c;
xfunc_error_retval = 2;
/* Parse command line options */
while ((c = getopt(argc, argv, optlist)) > 0) {
line = strchr(optlist, c);
if (!line) bb_show_usage();
switch (*line) {
#if ENABLE_FEATURE_SORT_BIG
case 'o':
if (outfile) bb_error_msg_and_die("too many -o");
outfile = xfopen(optarg, "w");
break;
case 't':
if (key_separator || optarg[1])
bb_error_msg_and_die("too many -t");
key_separator = *optarg;
break;
/* parse sort key */
case 'k': {
struct sort_key *key = add_key();
char *temp, *temp2;
temp = optarg;
for (i = 0; *temp;) {
/* Start of range */
key->range[2*i] = (unsigned short)strtol(temp, &temp, 10);
if (*temp == '.')
key->range[(2*i)+1] = (unsigned short)strtol(temp+1, &temp, 10);
for (; *temp; temp++) {
if (*temp == ',' && !i++) {
temp++;
break;
} /* no else needed: fall through to syntax error
because comma isn't in optlist */
temp2 = strchr(optlist, *temp);
flag = (1 << (temp2 - optlist));
if (!temp2 || (flag > FLAG_M && flag < FLAG_b))
bb_error_msg_and_die("unknown key option");
/* b after ',' means strip _trailing_ space */
if (i && flag == FLAG_b) flag = FLAG_bb;
key->flags |= flag;
}
}
break;
}
#endif
default:
global_flags |= (1 << (line - optlist));
/* global b strips leading and trailing spaces */
if (global_flags & FLAG_b) global_flags |= FLAG_bb;
break;
}
}
/* Open input files and read data */
for (i = argv[optind] ? optind : optind-1; argv[i]; i++) {
fp = stdin;
if (i >= optind && (argv[i][0] != '-' || argv[i][1]))
fp = xfopen(argv[i], "r");
for (;;) {
line = GET_LINE(fp);
if (!line) break;
if (!(linecount & 63))
lines = xrealloc(lines, sizeof(char *) * (linecount + 64));
lines[linecount++] = line;
}
fclose(fp);
}
#if ENABLE_FEATURE_SORT_BIG
/* if no key, perform alphabetic sort */
if (!key_list)
add_key()->range[0] = 1;
/* handle -c */
if (global_flags & FLAG_c) {
int j = (global_flags & FLAG_u) ? -1 : 0;
for (i = 1; i < linecount; i++)
if (compare_keys(&lines[i-1], &lines[i]) > j) {
fprintf(stderr, "Check line %d\n", i);
return 1;
}
return 0;
}
#endif
/* Perform the actual sort */
qsort(lines, linecount, sizeof(char *), compare_keys);
/* handle -u */
if (global_flags & FLAG_u) {
for (flag = 0, i = 1; i < linecount; i++) {
if (!compare_keys(&lines[flag], &lines[i]))
free(lines[i]);
else
lines[++flag] = lines[i];
}
if (linecount) linecount = flag+1;
}
/* Print it */
if (!outfile) outfile = stdout;
for (i = 0; i < linecount; i++)
fprintf(outfile, "%s\n", lines[i]);
fflush_stdout_and_exit(EXIT_SUCCESS);
}