Add a -n option to split(1) to split files into N chunks rather than

having to specify the right number of bytes.

Obtained from:	NetBSD
Submitted by:	Jan Schaumann <jschauma@netmeister.org>
PR:		113175

2 files changed, 78 insertions, 12 deletions

diff --git a/usr.bin/split/split.1 b/usr.bin/split/split.1
index 5e8e198..7825219 100644
--- a/usr.bin/split/split.1
+++ b/usr.bin/split/split.1
@@ -32,7 +32,7 @@
 .\"	@(#)split.1	8.3 (Berkeley) 4/16/94
 .\" $FreeBSD$
 .\"
-.Dd August 10, 2006
+.Dd March 16, 2008
 .Dt SPLIT 1
 .Os
 .Sh NAME
@@ -53,6 +53,10 @@
 .Op Fl a Ar suffix_length
 .Op Ar file Op Ar prefix
 .Nm
+.Fl n Ar chunk_count
+.Op Fl a Ar suffix_length
+.Op Ar file Op Ar prefix
+.Nm
 .Fl p Ar pattern
 .Op Fl a Ar suffix_length
 .Op Ar file Op Ar prefix
@@ -112,6 +116,10 @@ gigabyte pieces.
 Create smaller files
 .Ar line_count
 lines in length.
+.It Fl n Ar chunk_count
+Split file int
+.Ar chunk_count
+smaller files.
 .It Fl p Ar pattern
 The file is split whenever an input line matches
 .Ar pattern ,
diff --git a/usr.bin/split/split.c b/usr.bin/split/split.c
index d7936b0..22818e4 100644
--- a/usr.bin/split/split.c
+++ b/usr.bin/split/split.c
@@ -45,6 +45,8 @@ static const char sccsid[] = "@(#)split.c	8.2 (Berkeley) 4/16/94";
 #endif
 
 #include <sys/param.h>
+#include <sys/types.h>
+#include <sys/stat.h>
 
 #include <ctype.h>
 #include <err.h>
@@ -64,6 +66,7 @@ static const char sccsid[] = "@(#)split.c	8.2 (Berkeley) 4/16/94";
 #define DEFLINE	1000			/* Default num lines per file. */
 
 off_t	 bytecnt;			/* Byte count to split on. */
+off_t	 chunks = 0;			/* Chunks count to split into. */
 long	 numlines;			/* Line count to split on. */
 int	 file_open;			/* If a file open. */
 int	 ifd = -1, ofd = -1;		/* Input/output file descriptors. */
@@ -73,9 +76,10 @@ regex_t	 rgx;
 int	 pflag;
 long	 sufflen = 2;			/* File name suffix length. */
 
-void newfile(void);
-void split1(void);
-void split2(void);
+static void newfile(void);
+static void split1(void);
+static void split2(void);
+static void split3(void);
 static void usage(void);
 
 int
@@ -88,7 +92,7 @@ main(int argc, char **argv)
 
 	setlocale(LC_ALL, "");
 
-	while ((ch = getopt(argc, argv, "0123456789a:b:l:p:")) != -1)
+	while ((ch = getopt(argc, argv, "0123456789a:b:l:n:p:")) != -1)
 		switch (ch) {
 		case '0': case '1': case '2': case '3': case '4':
 		case '5': case '6': case '7': case '8': case '9':
@@ -138,6 +142,15 @@ main(int argc, char **argv)
 				errx(EX_USAGE,
 				    "%s: illegal line count", optarg);
 			break;
+		case 'n':		/* Chunks. */
+			if (!isdigit((unsigned char)optarg[0]) ||
+			    (chunks = (size_t)strtoul(optarg, &ep, 10)) == 0 ||
+			    *ep != '\0') {
+				errx(EX_USAGE, "%s: illegal number of chunks",
+				     optarg);
+			}
+			break;
+
 		case 'p':		/* pattern matching. */
 			if (regcomp(&rgx, optarg, REG_EXTENDED|REG_NOSUB) != 0)
 				errx(EX_USAGE, "%s: illegal regexp", optarg);
@@ -164,12 +177,15 @@ main(int argc, char **argv)
 
 	if (strlen(fname) + (unsigned long)sufflen >= sizeof(fname))
 		errx(EX_USAGE, "suffix is too long");
-	if (pflag && (numlines != 0 || bytecnt != 0))
+	if (pflag && (numlines != 0 || bytecnt != 0 || chunks != 0))
 		usage();
 
 	if (numlines == 0)
 		numlines = DEFLINE;
-	else if (bytecnt != 0)
+	else if (bytecnt != 0 || chunks != 0)
+		usage();
+
+	if (bytecnt && chunks)
 		usage();
 
 	if (ifd == -1)				/* Stdin by default. */
@@ -178,6 +194,9 @@ main(int argc, char **argv)
 	if (bytecnt) {
 		split1();
 		exit (0);
+	} else if (chunks) {
+		split3();
+		exit (0);
 	}
 	split2();
 	if (pflag)
@@ -189,12 +208,15 @@ main(int argc, char **argv)
  * split1 --
  *	Split the input by bytes.
  */
-void
+static void
 split1(void)
 {
 	off_t bcnt;
 	char *C;
 	ssize_t dist, len;
+	int nfiles;
+
+	nfiles = 0;
 
 	for (bcnt = 0;;)
 		switch ((len = read(ifd, bfr, MAXBSIZE))) {
@@ -204,8 +226,12 @@ split1(void)
 			err(EX_IOERR, "read");
 			/* NOTREACHED */
 		default:
-			if (!file_open)
-				newfile();
+			if (!file_open) {
+				if (!chunks || (nfiles < chunks)) {
+					newfile();
+					nfiles++;
+				}
+			}
 			if (bcnt + len >= bytecnt) {
 				dist = bytecnt - bcnt;
 				if (write(ofd, bfr, dist) != dist)
@@ -213,13 +239,19 @@ split1(void)
 				len -= dist;
 				for (C = bfr + dist; len >= bytecnt;
 				    len -= bytecnt, C += bytecnt) {
+					if (!chunks || (nfiles < chunks)) {
 					newfile();
+						nfiles++;
+					}
 					if (write(ofd,
 					    C, bytecnt) != bytecnt)
 						err(EX_IOERR, "write");
 				}
 				if (len != 0) {
+					if (!chunks || (nfiles < chunks)) {
 					newfile();
+						nfiles++;
+					}
 					if (write(ofd, C, len) != len)
 						err(EX_IOERR, "write");
 				} else
@@ -237,7 +269,7 @@ split1(void)
  * split2 --
  *	Split the input by lines.
  */
-void
+static void
 split2(void)
 {
 	long lcnt = 0;
@@ -286,10 +318,35 @@ writeit:
 }
 
 /*
+ * split3 --
+ *	Split the input into specified number of chunks
+ */
+static void
+split3(void)
+{
+	struct stat sb;
+
+	if (fstat(ifd, &sb) == -1) {
+		err(1, "stat");
+		/* NOTREACHED */
+	}
+
+	if (chunks > sb.st_size) {
+		errx(1, "can't split into more than %d files",
+		    (int)sb.st_size);
+		/* NOTREACHED */
+	}
+
+	bytecnt = sb.st_size / chunks;
+	split1();
+}
+
+
+/*
  * newfile --
  *	Open a new output file.
  */
-void
+static void
 newfile(void)
 {
 	long i, maxfiles, tfnum;
@@ -338,6 +395,7 @@ usage(void)
 	(void)fprintf(stderr,
 "usage: split [-l line_count] [-a suffix_length] [file [prefix]]\n"
 "       split -b byte_count[K|k|M|m|G|g] [-a suffix_length] [file [prefix]]\n"
+"       split -n chunk_count [-a suffix_length] [file [prefix]]\n"
 "       split -p pattern [-a suffix_length] [file [prefix]]\n");
 	exit(EX_USAGE);
 }