sbase/sort.c
Jakob Kramer 403b047a30 sort: allow keys where start_col > end_col
Useful in (rare) cases like:

	$ printf 'aaaa c\nx a\n0 b\n' | sort -k 2,1.3

And this is how POSIX wants it.
2015-04-06 17:15:54 +01:00

330 lines
6.3 KiB
C

/* See LICENSE file for copyright and license details. */
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "text.h"
#include "util.h"
struct keydef {
int start_column;
int end_column;
int start_char;
int end_char;
int flags;
};
enum {
MOD_N = 1 << 1,
MOD_STARTB = 1 << 2,
MOD_ENDB = 1 << 3,
MOD_R = 1 << 4,
};
struct kdlist {
struct keydef keydef;
struct kdlist *next;
};
static struct kdlist *head = NULL;
static struct kdlist *tail = NULL;
static void addkeydef(char *, int);
static void check(FILE *);
static int linecmp(const char **, const char **);
static int parse_flags(char **, int *, int);
static int parse_keydef(struct keydef *, char *, int);
static char *skipblank(char *);
static char *skipnonblank(char *);
static char *skipcolumn(char *, char *, int);
static char *columns(char *, const struct keydef *);
static int Cflag = 0, cflag = 0, uflag = 0;
static char *fieldsep = NULL;
static void
addkeydef(char *def, int flags)
{
struct kdlist *node;
node = enmalloc(2, sizeof(*node));
if (!head)
head = node;
if (parse_keydef(&node->keydef, def, flags))
enprintf(2, "faulty key definition\n");
if (tail)
tail->next = node;
node->next = NULL;
tail = node;
}
static void
check(FILE *fp)
{
static struct { char *buf; size_t size; } prev, cur, tmp;
if (!prev.buf && getline(&prev.buf, &prev.size, fp) < 0)
eprintf("getline:");
while (getline(&cur.buf, &cur.size, fp) > 0) {
if (uflag > linecmp((const char **) &cur.buf, (const char **) &prev.buf)) {
if (!Cflag)
weprintf("disorder: %s", cur.buf);
exit(1);
}
tmp = cur;
cur = prev;
prev = tmp;
}
}
static int
linecmp(const char **a, const char **b)
{
char *s1, *s2;
int res = 0;
long double x, y;
struct kdlist *node;
for (node = head; node && res == 0; node = node->next) {
s1 = columns((char *)*a, &node->keydef);
s2 = columns((char *)*b, &node->keydef);
/* if -u is given, don't use default key definition
* unless it is the only one */
if (uflag && node == tail && head != tail) {
res = 0;
} else if (node->keydef.flags & MOD_N) {
x = strtold(s1, NULL);
y = strtold(s2, NULL);
res = x < y ? -1 : x > y;
} else {
res = strcmp(s1, s2);
}
if (node->keydef.flags & MOD_R)
res = -res;
free(s1);
free(s2);
}
return res;
}
static int
parse_flags(char **s, int *flags, int bflag)
{
while (isalpha((int)**s)) {
switch (*((*s)++)) {
case 'b':
*flags |= bflag;
break;
case 'n':
*flags |= MOD_N;
break;
case 'r':
*flags |= MOD_R;
break;
default:
return -1;
}
}
return 0;
}
static int
parse_keydef(struct keydef *kd, char *s, int flags)
{
char *rest = s;
kd->start_column = 1;
kd->start_char = 1;
/* 0 means end of line */
kd->end_column = 0;
kd->end_char = 0;
kd->flags = flags;
kd->start_column = strtol(rest, &rest, 10);
if (kd->start_column < 1)
return -1;
if (*rest == '.')
kd->start_char = strtol(rest+1, &rest, 10);
if (kd->start_char < 1)
return -1;
if (parse_flags(&rest, &kd->flags, MOD_STARTB) < 0)
return -1;
if (*rest == ',') {
kd->end_column = strtol(rest+1, &rest, 10);
if (kd->end_column < 1)
return -1;
if (*rest == '.') {
kd->end_char = strtol(rest+1, &rest, 10);
if (kd->end_char < 0)
return -1;
}
if (parse_flags(&rest, &kd->flags, MOD_ENDB) < 0)
return -1;
}
return -(*rest);
}
static char *
skipblank(char *s)
{
while (isblank(*s))
s++;
return s;
}
static char *
skipnonblank(char *s)
{
while (*s && *s != '\n' && !isblank(*s))
s++;
return s;
}
static char *
skipcolumn(char *s, char *eol, int next_col)
{
if (fieldsep) {
if ((s = strstr(s, fieldsep)))
s += next_col ? strlen(fieldsep) : 0;
else
s = eol;
} else {
s = skipblank(s);
s = skipnonblank(s);
}
return s;
}
static char *
columns(char *line, const struct keydef *kd)
{
char *start, *end, *eol = strchr(line, '\n');
int i;
for (i = 1, start = line; i < kd->start_column; i++)
start = skipcolumn(start, eol, 1);
if (kd->flags & MOD_STARTB)
start = skipblank(start);
start = MIN(eol, start + kd->start_char - 1);
if (kd->end_column) {
for (i = 1, end = line; i < kd->end_column; i++)
end = skipcolumn(end, eol, 1);
if (kd->flags & MOD_ENDB)
end = skipblank(end);
if (kd->end_char)
end = MIN(eol, end + kd->end_char);
else
end = skipcolumn(end, eol, 0);
} else {
end = eol;
}
return enstrndup(2, start, start > end ? 0 : end - start);
}
static void
usage(void)
{
enprintf(2, "usage: %s [-Cbcmnru] [-o outfile] [-t delim] [-k def]... [file ...]\n", argv0);
}
int
main(int argc, char *argv[])
{
FILE *fp, *ofp = stdout;
struct linebuf linebuf = EMPTY_LINEBUF;
size_t i;
int global_flags = 0, ret = 0;
char *outfile = NULL;
ARGBEGIN {
case 'C':
Cflag = 1;
break;
case 'b':
global_flags |= MOD_STARTB | MOD_ENDB;
break;
case 'c':
cflag = 1;
break;
case 'k':
addkeydef(EARGF(usage()), global_flags);
break;
case 'm':
/* more or less for free, but for perfomance-reasons,
* we should keep this flag in mind and maybe some later
* day implement it properly so we don't run out of memory
* while merging large sorted files.
*/
break;
case 'n':
global_flags |= MOD_N;
break;
case 'o':
outfile = EARGF(usage());
break;
case 'r':
global_flags |= MOD_R;
break;
case 't':
fieldsep = EARGF(usage());
break;
case 'u':
uflag = 1;
break;
default:
usage();
} ARGEND;
/* -b shall only apply to custom key definitions */
if (!head && global_flags)
addkeydef("1", global_flags & ~(MOD_STARTB|MOD_ENDB));
addkeydef("1", global_flags & MOD_R);
if (!argc) {
if (Cflag || cflag) {
check(stdin);
} else {
getlines(stdin, &linebuf);
}
} else for (; *argv; argc--, argv++) {
if (!(fp = fopen(*argv, "r"))) {
enprintf(2, "fopen %s:", *argv);
continue;
}
if (Cflag || cflag) {
check(fp);
} else {
getlines(fp, &linebuf);
}
if (fshut(fp, *argv))
ret = 1;
}
if (!Cflag && !cflag) {
if (outfile && !(ofp = fopen(outfile, "w")))
eprintf("fopen %s:", outfile);
qsort(linebuf.lines, linebuf.nlines, sizeof *linebuf.lines,
(int (*)(const void *, const void *))linecmp);
for (i = 0; i < linebuf.nlines; i++) {
if (!uflag || i == 0 || linecmp((const char **)&linebuf.lines[i],
(const char **)&linebuf.lines[i-1])) {
fputs(linebuf.lines[i], ofp);
}
}
}
enfshut(2, stdin, "<stdin>");
enfshut(2, stdout, "<stdout>");
return ret;
}