busybox/coreutils/sort.c
2006-10-27 09:02:31 +00:00

323 lines
8.7 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 */
#ifdef CONFIG_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,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 && isspace(str[end]))
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 */
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;
#ifdef CONFIG_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;
#ifdef CONFIG_FEATURE_SORT_BIG
case FLAG_g:
{
char *xx,*yy;
double dx=strtod(x,&xx), 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),dy=atof(y);
retval=dx>dy ? 1 : (dx<dy ? -1 : 0);
break;
}
}
/* Free key copies. */
if(x!=*(char **)xarg) free(x);
if(y!=*(char **)yarg) free(y);
if(retval) break;
#else
/* Integer version of -n for tiny systems */
case FLAG_n:
retval=atoi(x)-atoi(y);
break;
}
#endif
}
/* Perform fallback sort if necessary */
if(!retval && !(global_flags&FLAG_s))
retval=strcmp(*(char **)xarg, *(char **)yarg);
return ((flags&FLAG_r)?-1:1)*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) {
#ifdef CONFIG_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++) {
if(i<optind || (*argv[i]=='-' && !argv[i][1])) fp=stdin;
else 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);
}
#ifdef CONFIG_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);
}