split: new -t option to select record separator

* src/split.c (eolchar): A new variable to hold
the separator character (unibyte for now).
This is reference throughout rather than hardcoding '\n'.
(usage): Describe the new --separator option, and
mention records along with lines so there is no ambiguity
that all options treat lines and records equivalently.
(main): Have -t update eolchar, or default to '\n'.
* tests/split/record-sep.sh: New test case.
* tests/local.mk: Reference the new test.
* doc/coreutils.texi (split invocation): Document the new option.
Adjust --lines, --line-bytes, --number=[lr]/... to mention
they pertain to records if --separator is specified.
* NEWS: Mention the new feature.

tests/split/record-sep.sh

@@ -0,0 +1,78 @@
+#!/bin/sh
+# test split with custom record separators
+
+# Copyright (C) 2015 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/>.
+
+. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
+print_ver_ split
+
+NL='
+'
+
+for sep in "$NL" '\0' ':'; do
+
+  test "$sep" = "$NL" && tr='\n' || tr="$sep"
+
+  for mode in '--lines=2' '--line-bytes=4' '--number=l/3' '--number=r/3'; do
+
+    # Generate in default mode for comparison
+    printf '1\n2\n3\n4\n5\n' > in || framework_failure_
+    split $mode in || fail=1
+    tr '\n' "$tr" < xaa > exp1
+    tr '\n' "$tr" < xab > exp2
+    tr '\n' "$tr" < xac > exp3
+
+    rm -f x??
+
+    # Generate output with specified --separator
+    printf '1\n2\n3\n4\n5\n' | tr '\n' "$tr" > in || framework_failure_
+    split $mode -t "$sep" in || fail=1
+
+    compare exp1 xaa || fail=1
+    compare exp2 xab || fail=1
+    compare exp3 xac || fail=1
+    test -f xad && fail=1
+  done
+
+done
+
+
+#
+# Test usage edge cases
+#
+
+# Should fail: '-t' requires an argument
+{ split -t </dev/null >/dev/null 2>/dev/null || test $? -ne 1; } &&
+  { warn_ "-t without argument did not trigger an error" ; fail=1 ; }
+
+# should fail: multi-character separator
+{ split -txx </dev/null >/dev/null 2>&1 || test $? -ne 1; } &&
+  { warn_ "-txx did not trigger an error" ; fail=1 ; }
+
+# should fail: different separators used
+{ split -ta -tb </dev/null >/dev/null 2>&1 || test $? -ne 1; } &&
+  { warn_ "-ta -tb did not trigger an error" ; fail=1 ; }
+
+# should fail: different separators used, including default
+{ split -t"$NL" -tb </dev/null >/dev/null 2>&1 || test $? -ne 1; } &&
+  { warn_ "-t\$NL -tb did not trigger an error" ; fail=1 ; }
+
+# should not fail: same separator used multiple times
+split -t: -t: </dev/null >/dev/null 2>&1 ||
+  { warn_ "-t: -t: triggered an error" ; fail=1 ; }
+
+
+Exit $fail