new utilities.

the .C files compile but are renamed to avoid building automatically.

src/cmd/split.c

@@ -0,0 +1,189 @@
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+#include <ctype.h>
+#include <regexp.h>
+
+char	digit[] = "0123456789";
+char	*suffix = "";
+char	*stem = "x";
+char	suff[] = "aa";
+char	name[200];
+Biobuf	bout;
+Biobuf	*output = &bout;
+
+extern int nextfile(void);
+extern int matchfile(Resub*);
+extern void openf(void);
+extern char *fold(char*,int);
+extern void usage(void);
+extern void badexp(void);
+
+void
+main(int argc, char *argv[])
+{
+	Reprog *exp;
+	char *pattern = 0;
+	int n = 1000;
+	char *line;
+	int xflag = 0;
+	int iflag = 0;
+	Biobuf bin;
+	Biobuf *b = &bin;
+	char buf[256];
+
+	ARGBEGIN {
+	case 'l':
+	case 'n':
+		n=atoi(EARGF(usage()));
+		break;
+	case 'e':
+		pattern = strdup(EARGF(usage()));
+		break;
+	case 'f':
+		stem = strdup(EARGF(usage()));
+		break;
+	case 's':
+		suffix = strdup(EARGF(usage()));
+		break;
+	case 'x':
+		xflag++;
+		break;
+	case 'i':
+		iflag++;
+		break;
+	default:
+		usage();
+		break;
+
+	} ARGEND;
+
+	if(argc < 0 || argc > 1)
+		usage();
+
+	if(argc != 0) {
+		b = Bopen(argv[0], OREAD);
+		if(b == nil) {
+			fprint(2, "split: can't open %s: %r\n", argv[0]);
+			exits("open");
+		}
+	} else
+		Binit(b, 0, OREAD);
+
+	if(pattern) {
+		if(!(exp = regcomp(iflag? fold(pattern,strlen(pattern)): pattern)))
+			badexp();
+		while((line=Brdline(b,'\n')) != 0) {
+			Resub match[2];
+			memset(match, 0, sizeof match);
+			line[Blinelen(b)-1] = 0;
+			if(regexec(exp,iflag?fold(line,Blinelen(b)-1):line,match,2)) {
+				if(matchfile(match) && xflag)
+					continue;
+			} else if(output == 0)
+				nextfile();	/* at most once */
+			Bwrite(output, line, Blinelen(b)-1);
+			Bputc(output, '\n');
+		}
+	} else {
+		int linecnt = n;
+
+		while((line=Brdline(b,'\n')) != 0) {
+			if(++linecnt > n) {
+				nextfile();
+				linecnt = 1;
+			}
+			Bwrite(output, line, Blinelen(b));
+		}
+
+		/*
+		 * in case we didn't end with a newline, tack whatever's 
+		 * left onto the last file
+		 */
+		while((n = Bread(b, buf, sizeof(buf))) > 0)
+			Bwrite(output, buf, n);
+	}
+	if(b != nil)
+		Bterm(b);
+	exits(0);
+}
+
+int
+nextfile(void)
+{
+	static int canopen = 1;
+	if(suff[0] > 'z') {
+		if(canopen)
+			fprint(2, "split: file %szz not split\n",stem);
+		canopen = 0;
+	} else {
+		strcpy(name, stem);
+		strcat(name, suff);
+		if(++suff[1] > 'z') 
+			suff[1] = 'a', ++suff[0];
+		openf();
+	}
+	return canopen;
+}
+
+int
+matchfile(Resub *match)
+{
+	if(match[1].s.sp) {
+		int len = match[1].e.ep - match[1].s.sp;
+		strncpy(name, match[1].s.sp, len);
+		strcpy(name+len, suffix);
+		openf();
+		return 1;
+	} 
+	return nextfile();
+}
+
+void
+openf(void)
+{
+	static int fd = 0;
+	Bflush(output);
+	Bterm(output);
+	if(fd > 0)
+		close(fd);
+	fd = create(name,OWRITE,0666);
+	if(fd < 0) {
+		fprint(2, "grep: can't create %s: %r\n", name);
+		exits("create");
+	}
+	Binit(output, fd, OWRITE);
+}
+
+char *
+fold(char *s, int n)
+{
+	static char *fline;
+	static int linesize = 0;
+	char *t;
+
+	if(linesize < n+1){
+		fline = realloc(fline,n+1);
+		linesize = n+1;
+	}
+	for(t=fline; *t++ = tolower(*s++); )
+		continue;
+		/* we assume the 'A'-'Z' only appear as themselves
+		 * in a utf encoding.
+		 */
+	return fline;
+}
+
+void
+usage(void)
+{
+	fprint(2, "usage: split [-n num] [-e exp] [-f stem] [-s suff] [-x] [-i] [file]\n");
+	exits("usage");
+}
+
+void
+badexp(void)
+{
+	fprint(2, "split: bad regular expression\n");
+	exits("bad regular expression");
+}