Initial commit

4 files changed, 278 insertions, 0 deletions

diff --git a/libsh/alias.sh b/libsh/alias.sh
new file mode 100644
index 0000000..2945910
--- /dev/null
+++ b/libsh/alias.sh
@@ -0,0 +1,56 @@
+# Copyright (C) 2016  Patrick "P. J." McDermott
+#
+# This file is part of libsh.
+#
+# libsh is free software: you can redistribute it and/or modify it
+# under the terms of the GNU Lesser General Public License as published
+# by the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# libsh 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 Lesser General Public
+# License along with libsh.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+static check_args()
+{
+	local params="${1}"
+	shift 1
+	local p=
+
+	IFS=' '
+	for p in ${params}; do
+		unset IFS
+		if ! [ ${#} -gt 0 ]; then
+			return 1
+		fi
+		case "${p}" in
+			'string')
+				;;
+			'int')
+				case "${1}" in *[!0-9]*) return 1;; esac
+				;;
+		esac
+		shift 1
+	done
+	unset IFS
+
+	if ! [ ${#} -eq 0 ]; then
+		return 1
+	fi
+
+	return 0
+}
+
+__alias()
+{
+	local fn="${1}"
+	local alias="${2}"
+	local params="${*}"
+
+	eval "${alias}() { ${check_args} \"\${params}\" \"\${@}\" && ${fn}; }"
+}
diff --git a/libsh/errno.sh b/libsh/errno.sh
new file mode 100644
index 0000000..a0f9648
--- /dev/null
+++ b/libsh/errno.sh
@@ -0,0 +1,53 @@
+# Copyright (C) 2016  Patrick "P. J." McDermott
+#
+# This file is part of libsh.
+#
+# libsh is free software: you can redistribute it and/or modify it
+# under the terms of the GNU Lesser General Public License as published
+# by the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# libsh is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with libsh.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+static errlist='
+	EINVAL   1
+	EUNK     2
+	EMFILE   3
+	EACCES   4
+	ENOENT   5
+	EISDIR   6
+	EBADF    7
+	'
+
+static strerror()
+{
+	local errnum=${1}
+
+	eval "msgget \"\${__errsym_${errnum}}\""
+}
+
+static init_error_syms()
+{
+	IFS=' '
+	while read errsym errno; do
+		eval "${errsym}=${errno}"
+		eval "__errsym_${errno}=${errsym}"
+	done <<-EOF
+		${errlist}
+		EOF
+	unset IFS
+}
+__init ${init_error_syms}
+
+static errno_alias()
+{
+	__alias ${strerror} strerror int
+}
+__init ${errno_alias}
diff --git a/libsh/rand.sh b/libsh/rand.sh
new file mode 100644
index 0000000..07347d3
--- /dev/null
+++ b/libsh/rand.sh
@@ -0,0 +1,46 @@
+# Copyright (C) 2014, 2016  Patrick "P. J." McDermott
+#
+# This file is part of libsh.
+#
+# libsh is free software: you can redistribute it and/or modify it
+# under the terms of the GNU Lesser General Public License as published
+# by the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# libsh is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with libsh.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+RAND_MAX=2147483647  # 2^31 - 1
+
+static x=1
+
+rand_x=1
+
+static srand()
+{
+	local s="${1}"
+
+	x=${s}
+	rand_x=${s}
+}
+
+static rand()
+{
+	# Multiplier, increment, and modulus values are those used in glibc.
+	x=$((1103515245 * ${x} + 12345))
+	x=$((${x} % (${RAND_MAX} + 1)))
+	rand_x=${x}
+}
+
+static rand_alias()
+{
+	__alias ${srand} srand int
+	__alias ${rand} rand
+}
+__init ${rand_alias}
diff --git a/libsh/stdio.sh b/libsh/stdio.sh
new file mode 100644
index 0000000..7d44d12
--- /dev/null
+++ b/libsh/stdio.sh
@@ -0,0 +1,123 @@
+# Copyright (C) 2013, 2016  Patrick "P. J." McDermott
+#
+# This file is part of libsh.
+#
+# libsh is free software: you can redistribute it and/or modify it
+# under the terms of the GNU Lesser General Public License as published
+# by the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# libsh is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with libsh.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+# Shells and the file descriptors they reserve for the user:
+#   * Debian Almquist Shell
+#     - The shell doesn't understand any file descriptor greater than 9.
+#     - File descriptors starting at 10 are used for I/O redirection.
+#   * BusyBox ash
+#     - File descriptors starting at 10 are used for job control and I/O
+#       redirection.
+#   * GNU Bash:
+#     - GNU Readline uses file descriptor 255 in interactive shells.
+#     - File descriptors starting at 10 are used for I/O redirection.
+#   * MirOS Korn Shell
+#     - File descriptors starting at either 10 or 24 are used for the shell's
+#       tty_fd and shl_dbg_fd.
+#   * Solaris ksh
+#     - The shell doesn't understand any file descriptor greater than 9.
+static fd_min=3
+static fd_max=9
+
+static fd_3_set=false
+static fd_4_set=false
+static fd_5_set=false
+static fd_6_set=false
+static fd_7_set=false
+static fd_8_set=false
+static fd_9_set=false
+
+fd=0
+
+static fopen()
+{
+	local path="${1}"
+	local mode="${2}"
+	local mode_r=
+	local mode_w=
+	local i=
+	local f=
+
+	case "${mode}" in
+		'r')  mode_r=true  mode_w=false mode='<' ;;
+		'r+') mode_r=true  mode_w=true  mode='<>';;
+		'w')  mode_r=false mode_w=true  mode='>' ;;
+		'a')  mode_r=false mode_w=true  mode='>>';;
+		*) return ${EINVAL};;
+	esac
+
+	# Find first available file descriptor.
+	i=${fd_min}
+	while [ ${i} -le ${fd_max} ]; do
+		if ! $(eval "printf '%s' \${fd_${i}_set}"); then
+			f=${i}
+			break
+		fi
+		i=$(($i + 1))
+	done
+	if [ "x${f}" = 'x' ]; then
+		return ${EMFILE}
+	fi
+
+	# Check file mode and existence.
+	if ${mode_r} && ! [ -r "${path}" ]; then
+		return ${EACCES}
+	fi
+	if ${mode_w} && ! [ -w "${path}" ]; then
+		return ${EACCES}
+	fi
+	if ! [ -e "${path}" ]; then
+		return ${ENOENT}
+	fi
+	if [ -d "${path}" ]; then
+		return ${EISDIR}
+	fi
+
+	if ! eval "exec ${f}${mode}'${path}'" 2>/dev/null; then
+		return ${EUNK}
+	fi
+
+	eval "fd_${f}_set=true"
+	fd="${f}"
+	return 0
+}
+
+static fclose()
+{
+	local f=${1}
+
+	# Make sure the file descriptor is valid and open.
+	if [ ${f} -lt ${fd_min} ] || [ ${f} -gt ${fd_max} ]; then
+		return ${EINVAL}
+	fi
+	if $(eval "printf '%s' \${fd_${i}_set}"); then
+		return ${EBADF}
+	fi
+
+	eval "exec ${f}>&-"
+	unset "fd_${f}"
+
+	return 0
+}
+
+static stdio_alias()
+{
+	__alias ${fopen} fopen string string
+	__alias ${fclose} fclose int
+}
+__init ${stdio_alias}