1 files changed, 59 insertions, 0 deletions
diff --git a/tests/misc/head-c.sh b/tests/misc/head-c.sh
new file mode 100755
index 0000000..7655ff3
--- /dev/null
+++ b/tests/misc/head-c.sh
@@ -0,0 +1,59 @@
+#!/bin/sh
+# exercise head -c
+
+# Copyright (C) 2001-2022 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 <https://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
+print_ver_ head
+getlimits_
+
+vm=$(get_min_ulimit_v_ head -c1 /dev/null) \
+  || skip_ "this shell lacks ulimit support"
+
+# exercise the fix of 2001-08-18, based on test case from Ian Bruce
+echo abc > in || framework_failure_
+(head -c1; head -c1) < in > out || fail=1
+case "$(cat out)" in
+  ab) ;;
+  *) fail=1 ;;
+esac
+
+# Test for a bug in coreutils 5.0.1 through 8.22.
+printf 'abc\ndef\n' > in1 || framework_failure_
+(dd bs=1 skip=1 count=0 status=none && head -c-4) < in1 > out1 || fail=1
+case "$(cat out1)" in
+  bc) ;;
+  *) fail=1 ;;
+esac
+
+# Only allocate memory as needed.
+# Coreutils <= 8.21 would allocate memory up front
+# based on the value passed to -c
+(ulimit -v $(($vm+8000)) && head --bytes=-$SSIZE_MAX < /dev/null) || fail=1
+
+# Make sure it works on funny files in /proc and /sys.
+
+for file in /proc/version /sys/kernel/profiling; do
+  if test -r $file; then
+    cp -f $file copy &&
+    head -c -1 copy > exp1 || framework_failure_
+
+    head -c -1 $file > out1 || fail=1
+    compare exp1 out1 || fail=1
+  fi
+done
+
+Exit $fail