(devopsdaysGH-641) Add Wercker step to check for invalid Windows file…

…names

This commit adds a helper script (build/check-invalid-filenames.sh)
which processes the file and directory names in the repoistory and
reports an error if it finds names which would be invalid on a
Windows filesystem.

This commit configures Wercker to run the validation script prior to
building via Hugo.  The script will fail on the first file it finds.
To list all invalid files, set environment variable NO_EXIT_ON_FAILURE
and the script will list all errors on STDERR but emit a zero exit code.

build/check-invalid-filenames.sh

@@ -0,0 +1,83 @@
+#!/bin/bash
+#
+# Original copyright thomas dot braun aeht virtuell minus zuhause dot de,  2013
+# https://github.com/t-b/git-pre-commit-hook-windows-filenames
+#
+# Sources:
+# - http://stackoverflow.com/a/62888
+# - http://msdn.microsoft.com/en-us/library/aa365247.aspx
+
+# Redirect output to stderr.
+exec 1>&2
+
+find . -type f -not -path "*.git*" | while read filename; do
+  # Strip leading period
+  filename="${filename#.}"
+
+  # Non-printable characters from ASCII range 0-31 
+  nonprintablechars=$(echo -n "$filename" | LC_ALL=C tr -d '[ -~]' | wc -c)
+
+  # Illegal characters: < > : " / \ | ? *
+  # We don't test for / (forward slash) here as that is even on *nix not allowed in *filename*
+  illegalchars=$(echo -n "$filename" | LC_ALL=C grep -E '(<|>|:|"|\\|\||\?|\*)' | wc -c)
+
+  # Reserved names plus possible extension
+  # CON, PRN, AUX, NUL, COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8, COM9, LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, and LPT9
+  reservednames=0 #$(echo -n "$filename" | LC_ALL=C grep -i -E '(CON|PRN|AUX|NUL|COM1|COM2|COM3|COM4|COM5|COM6|COM7|COM8|COM9|LPT1|LPT2|LPT3|LPT4|LPT5|LPT6|LPT7|LPT8|LPT9).[a-z]{3}' | wc -c)
+
+  # No trailing period or space
+  trailingperiodorspace=$(echo -n "$filename" | LC_ALL=C grep -E '(\.| )$' | wc -c)
+
+  # File name is all periods
+  filenameallperiods=$(echo -n "$filename" | LC_ALL=C grep -E '^\.+$' | wc -c)
+
+  # Check complete path length to be smaller than 260 characters
+  # This test can not be really accurate as we don't know if PWD on the windows filesystem itself is not very long 
+  absolutepathtoolong=0
+  if test $(echo "$filename" | wc -c) -ge 260
+  then
+    absolutepathtoolong=1
+  fi
+
+  # debug output
+  if test $nonprintablechars -ne 0 \
+     || test $illegalchars -ne 0 \
+     || test $reservednames -ne 0 \
+     || test $trailingperiodorspace -ne 0 \
+     || test $filenameallperiods -ne 0 \
+     || test $absolutepathtoolong -ne 0
+  then
+    echo "Error: File name is incompatible to windows file systems."
+    echo "File: ${filename}"
+    if test $nonprintablechars -ne 0
+    then
+      echo Error: nonprintablechars=$nonprintablechars
+    fi
+    if test $illegalchars -ne 0
+    then
+      echo Error: illegalchars=$illegalchars
+    fi
+    if test $reservednames -ne 0
+    then
+      echo Error: reservednames=$reservednames
+    fi
+    if test $trailingperiodorspace -ne 0
+    then
+      echo Error: trailingperiodorspace=$trailingperiodorspace
+    fi
+    if test $filenameallperiods -ne 0
+    then
+      echo Error: filenameallperiods=$filenameallperiods
+    fi
+    if test $absolutepathtoolong -ne 0
+    then
+      echo Error: absolutepathtoolong=$absolutepathtoolong
+    fi
+
+    # If the env. var 'NO_EXIT_ON_FAILURE' is set then don't exit, otherwise exit with non-zero
+    if [ -z ${NO_EXIT_ON_FAILURE+x} ]
+    then
+      exit 1
+    fi
+  fi
+done

wercker.yml

@@ -1,6 +1,9 @@
 box: debian
 build:
   steps:
+    - script:
+        name: Check for filenames not valid on Windows
+        code: build/check-invalid-filenames.sh
     - arjen/hugo-build:
         version: "0.15"
         theme: devopsdays-responsive