Rename: nix-script.sh -> nix-script

1 files changed, 150 insertions, 0 deletions

diff --git a/nix-script b/nix-script
new file mode 100755
index 0000000..5c38c45
--- /dev/null
+++ b/nix-script
@@ -0,0 +1,150 @@
+#!/bin/bash
+
+#
+# To be written
+#
+# Wrapper script for calling other scripts like so:
+#
+#   nix-script diff-generations 1 2
+#
+# So the "diff-generations" script looks like a command for "nix-script"
+#
+
+usage() {
+    cat <<EOS >&2
+    $(basename $0) [options] <command> <commandoptions>
+
+    -l | --list-commands    List all available commands
+    -c | --config           Use alternative configuration (rc) file
+    -v                      Be verbose
+    -h                      Show this help and exit
+
+    (c) 2015 Matthias Beyer
+    GPLv2 licensed
+EOS
+}
+
+LIST_COMMANDS=0
+VERBOSE=0
+CONFIGFILE=~/.nixscriptsrc
+
+stderr() {
+    echo "[$(basename $0)]: $*" >&2
+}
+
+stdout() {
+    [ $VERBOSE -eq 1 ] && echo "[$(basename $0)]: $*"
+}
+
+script_for() {
+    echo "$(dirname ${BASH_SOURCE[0]})/nix-script-${1}.sh"
+}
+
+SHIFT_ARGS=0
+shift_one_more() {
+    SHIFT_ARGS=$(( SHIFT_ARGS + 1 ))
+}
+
+shift_n() {
+    for n in `seq 0 $1`; do shift; done
+    echo $*
+}
+
+all_commands() {
+    find $(dirname ${BASH_SOURCE[0]}) -type f -name "nix-script-*.sh"
+}
+
+for cmd
+do
+    case $cmd in
+    "--list-commands" )
+        LIST_COMMANDS=1
+        shift_one_more
+        ;;
+
+    "-l" )
+        LIST_COMMANDS=1
+        shift_one_more
+        ;;
+
+    "--config" )
+        CONFIGFILE=$1
+        shift_one_more
+        ;;
+
+    "-c" )
+        CONFIGFILE=$1
+        shift_one_more
+        ;;
+
+    "-v" )
+        export VERBOSE=1
+        stdout "Verbose now"
+        shift_one_more
+        ;;
+
+    "-h" )
+        usage
+        exit 1
+        ;;
+
+    * )
+        if [ ! -n $(script_for $cmd) ]
+        then
+            stderr "Unknown flag / command '$cmd'"
+            exit 1
+        else
+            if [ -z "$COMMAND" ]
+            then
+                stdout "Found command: '$cmd'"
+                COMMAND=$cmd
+                shift_one_more
+            fi
+        fi
+    esac
+done
+
+if [ ! -f $CONFIGFILE ]
+then
+    stderr "No config file: '$CONFIGFILE', won't override defaults"
+else
+    stdout "Source config: '$CONFIGFILE'"
+    . $CONFIFILE
+fi
+
+if [ $LIST_COMMANDS -eq 1 ]
+then
+    stdout "Listing commands"
+    for cmd in $(all_commands)
+    do
+        echo "$cmd"
+    done
+    exit 0
+fi
+
+if [ -z "$COMMAND" ]
+then
+    stderr "No command given"
+    exit 0
+fi
+
+stdout "Searching for script for '$COMMAND'"
+SCRIPT=$(script_for $COMMAND)
+
+if [ ! -f $SCRIPT ]
+then
+    stderr "Not available: $COMMAND -> $SCRIPT"
+    exit 1
+fi
+
+if [[ ! -x $SCRIPT ]]
+then
+    stderr "Not executeable: $SCRIPT"
+    exit 1
+fi
+
+stdout "Parsing args for '$COMMAND'"
+SCRIPT_ARGS=$(shift_n $SHIFT_ARGS $*)
+
+stdout "Calling: '$COMMAND $SCRIPT_ARGS'"
+exec bash $SCRIPT $SCRIPT_ARGS