split: add --number to generate a particular number of files

* src/split.c (usage, long_options, main): New options --number,
--unbuffered, --elide-empty-files.
(set_suffix_length): New function to auto increase suffix length
to handle a specified number of files.
(create): New function.  Refactored from cwrite() and ofile_open().
(bytes_split): Add max_files argument to support byte chunking.
(lines_chunk_split): New function.  Split file into chunks of lines.
(bytes_chunk_extract): New function.  Extract a chunk of file.
(of_info): New struct.  Used by functions lines_rr and ofile_open
to keep track of file descriptors associated with output files.
(ofile_open): New function.  Shuffle file descriptors when there
are more output files than available file descriptors.
(lines_rr): New function to distribute lines round-robin to files.
(chunk_parse): New function.  Parses K/N syntax.
* tests/misc/split-bchunk: New test for byte chunking.
* tests/misc/split-lchunk: New test for line delimited chunking.
* tests/misc/split-rchunk: New test for round-robin chunking.
* tests/Makefile.am: Reference new tests.
* tests/misc/split-fail: Add failure scenarios for new options.
* tests/misc/split-l: Fix a typo. s/ln/split/.
* doc/coreutils.texi (split invocation): Document --number.
* NEWS: Mention the new feature.
* .mailmap: Map new email address for shortlog.

Signed-off-by: Pádraig Brady <P@draigBrady.com>

6 files changed, 247 insertions, 1 deletions

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 971f427ce..2e33063bd 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -240,8 +240,11 @@ TESTS =						\
   misc/sort-unique				\
   misc/sort-version				\
   misc/split-a					\
+  misc/split-bchunk				\
   misc/split-fail				\
   misc/split-l					\
+  misc/split-lchunk				\
+  misc/split-rchunk				\
   misc/stat-birthtime				\
   misc/stat-fmt					\
   misc/stat-hyphen				\
diff --git a/tests/misc/split-bchunk b/tests/misc/split-bchunk
new file mode 100755
index 000000000..aef450bb7
--- /dev/null
+++ b/tests/misc/split-bchunk
@@ -0,0 +1,50 @@
+#!/bin/sh
+# test splitting into 3 chunks
+
+# Copyright (C) 2010 Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/init.sh"; path_prepend_ ../src
+print_ver_ split
+
+# N can be greater than the file size
+# in which case no data is extracted, or empty files are written
+split -n 10 /dev/null || fail=1
+test "$(stat -c %s x* | uniq -c | sed 's/^ *//; s/ /x/')" = "10x0" || fail=1
+rm x??
+
+# Ensure --elide-empty-files is honored
+split -e -n 10 /dev/null || fail=1
+stat x?? 2>/dev/null && fail=1
+
+printf '1\n2\n3\n4\n5\n' > in || framework_failure
+
+split -n 3 in > out || fail=1
+split -n 1/3 in > b1 || fail=1
+split -n 2/3 in > b2 || fail=1
+split -n 3/3 in > b3 || fail=1
+printf '1\n2' > exp-1
+printf '\n3\n' > exp-2
+printf '4\n5\n' > exp-3
+
+compare xaa exp-1 || fail=1
+compare xab exp-2 || fail=1
+compare xac exp-3 || fail=1
+compare b1 exp-1 || fail=1
+compare b2 exp-2 || fail=1
+compare b3 exp-3 || fail=1
+test -f xad && fail=1
+
+Exit $fail
diff --git a/tests/misc/split-fail b/tests/misc/split-fail
index b0b22e4c4..cf0edc900 100755
--- a/tests/misc/split-fail
+++ b/tests/misc/split-fail
@@ -27,6 +27,10 @@ split -a 0 in 2> /dev/null || fail=1
 split -b 0 in 2> /dev/null && fail=1
 split -C 0 in 2> /dev/null && fail=1
 split -l 0 in 2> /dev/null && fail=1
+split -n 0 in 2> /dev/null && fail=1
+split -n 1/0 in 2> /dev/null && fail=1
+split -n 0/1 in 2> /dev/null && fail=1
+split -n 2/1 in 2> /dev/null && fail=1
 
 # Make sure -C doesn't create empty files.
 rm -f x?? || fail=1
@@ -44,6 +48,12 @@ split --lines=$UINTMAX_MAX in || fail=1
 split --bytes=$OFF_T_MAX in || fail=1
 split --line-bytes=$OFF_T_OFLOW 2> /dev/null in && fail=1
 split --line-bytes=$SIZE_OFLOW 2> /dev/null in && fail=1
+if truncate -s$SIZE_OFLOW large; then
+  # Ensure we can split chunks of a large file on 32 bit hosts
+  split --number=$SIZE_OFLOW/$SIZE_OFLOW large >/dev/null || fail=1
+fi
+split --number=r/$UINTMAX_MAX/$UINTMAX_MAX </dev/null >/dev/null || fail=1
+split --number=r/$UINTMAX_OFLOW </dev/null 2>/dev/null && fail=1
 
 # Make sure that a huge obsolete option evokes the right failure.
 split -99999999999999999991 2> out && fail=1
diff --git a/tests/misc/split-l b/tests/misc/split-l
index 8967439e8..428e2018c 100755
--- a/tests/misc/split-l
+++ b/tests/misc/split-l
@@ -17,7 +17,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 . "${srcdir=.}/init.sh"; path_prepend_ ../src
-print_ver_ ln
+print_ver_ split
 
 printf '1\n2\n3\n4\n5\n' > in || framework_failure
 
diff --git a/tests/misc/split-lchunk b/tests/misc/split-lchunk
new file mode 100755
index 000000000..4c7c20e0e
--- /dev/null
+++ b/tests/misc/split-lchunk
@@ -0,0 +1,117 @@
+#!/bin/sh
+# test splitting into newline delineated chunks (-n l/...)
+
+# Copyright (C) 2010 Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/init.sh"; path_prepend_ ../src
+print_ver_ split
+
+# invalid number of chunks
+echo 'split: 1o: invalid number of chunks' > exp
+split -n l/1o 2>err && fail=1
+compare err exp || fail=1
+
+echo "split: \`-': cannot determine file size" > exp
+echo | split -n l/1 2>err && fail=1
+compare err exp || fail=1
+
+# N can be greater than the file size
+# in which case no data is extracted, or empty files are written
+split -n l/10 /dev/null || fail=1
+test "$(stat -c %s x* | uniq -c | sed 's/^ *//; s/ /x/')" = "10x0" || fail=1
+rm x??
+
+# Ensure --elide-empty-files is honored
+split -e -n l/10 /dev/null || fail=1
+stat x?? 2>/dev/null && fail=1
+
+# 80 bytes. ~ transformed to \n below
+lines=\
+12345~1~12345~1~12345~1~12345~1~12345~~~12345~1~12345~1~12345~1~12345~1~12345~1~
+
+printf "%s" "$lines" | tr '~' '\n' > in || framework_failure
+
+echo 'split: 16: invalid chunk number' > exp
+split -n l/16/15 in 2>err && fail=1
+compare err exp || fail=1
+
+: > out
+printf '%s' "\
+14 16 09 15 16 10
+14 08 08 10 14 08 08 10
+06 08 08 02 06 08 08 02 06 08 08 10
+06 08 02 06 08 00 08 02 06 08 02 06 08 00 10
+06 00 08 00 02 06 00 02 06 00 08 00 01 07 00 02 06 00 08 00 02 16
+" > exp || framework_failure
+
+# Note for full testing one should set bufsize to 1,2,5,10,80,100
+# at the start of lines_chunk_split(), for each run of this test.
+
+DEBUGGING=
+test "$DEBUGGING" && test "$VERBOSE" && set +x
+for N in 6 8 12 15 22; do
+  rm -f x*
+  split -n l/$N in
+  echo $(stat -c "%02s" x*) >> out
+
+  if test "$DEBUGGING"; then
+    # Output partition pattern
+    size=$(printf "%s" "$lines" | wc -c)
+    chunk_size=$(($size/$N))
+    end_size=$(($chunk_size + ($size % $N)))
+    {
+      yes "$(printf %${chunk_size}s ])" | head -n$(($N-1))
+      printf %${end_size}s ]
+    } | tr -d '\n' | sed "s/\\(^.\\{1,$size\\}\\).*/\\1/"
+    echo
+
+    # Output pattern generated for comparison
+    for s in $(stat -c "%s" x*); do
+      #s=0 transitions are not shown
+      test "$m" = "_" && m=- || m=_
+      printf "%${s}s" '' | tr ' ' $m
+    done
+    echo
+
+    # Output lines for reference
+    echo "$lines"
+  fi
+done
+test "$DEBUGGING" && test "$VERBOSE" && set -x
+
+compare out exp || fail=1
+
+# Check extraction of particular chunks
+: > out
+printf '1\n12345\n' > exp
+split -n l/13/15 in > out
+compare out exp || fail=1
+: > out
+printf '' > exp
+split -n l/14/15 in > out
+compare out exp || fail=1
+: > out
+printf '1\n12345\n1\n' > exp
+split -n l/15/15 in > out
+compare out exp || fail=1
+
+# test input with no \n at end
+printf '12\n34\n5' > in
+printf '5' > exp
+split -n l/7/7 in > out
+compare out exp || fail=1
+
+Exit $fail
diff --git a/tests/misc/split-rchunk b/tests/misc/split-rchunk
new file mode 100755
index 000000000..3957f73cc
--- /dev/null
+++ b/tests/misc/split-rchunk
@@ -0,0 +1,66 @@
+#!/bin/sh
+# test splitting into round-robin chunks
+
+# Copyright (C) 2010 Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/init.sh"; path_prepend_ ../src
+print_ver_ split
+
+require_ulimit_
+
+# N can be greater than the file size
+# in which case no data is extracted, or empty files are written
+split -n r/10 /dev/null || fail=1
+test "$(stat -c %s x* | uniq -c | sed 's/^ *//; s/ /x/')" = "10x0" || fail=1
+rm x??
+
+# Ensure --elide-empty-files is honored
+split -e -n r/10 /dev/null || fail=1
+stat x?? 2>/dev/null && fail=1
+
+printf '1\n2\n3\n4\n5\n' > in || framework_failure
+
+split -n r/3 in > out || fail=1
+test -s out && fail=1
+
+split -n r/1/3 in > r1 || fail=1
+split -n r/2/3 in > r2 || fail=1
+split -n r/3/3 in > r3 || fail=1
+
+printf '1\n4\n' > exp-1
+printf '2\n5\n' > exp-2
+printf '3\n' > exp-3
+
+compare xaa exp-1 || fail=1
+compare xab exp-2 || fail=1
+compare xac exp-3 || fail=1
+compare r1 exp-1 || fail=1
+compare r2 exp-2 || fail=1
+compare r3 exp-3 || fail=1
+test -f xad && fail=1
+
+# Test input without trailing \n
+printf '1\n2\n3\n4\n5' | split -n r/2/3 > out
+printf '2\n5' > exp
+compare out exp || fail=1
+
+# Ensure we fall back to appending to a file at a time
+# if we hit the limit for the number of open files.
+rm x*
+(ulimit -n 20 && yes | head -n90 | split -n r/30 ) || fail=1
+test "$(stat -c %s x* | uniq -c | sed 's/^ *//; s/ /x/')" = "30x6" || fail=1
+
+Exit $fail