---input---
BoOtStRaP: library  # pass: headers are case-insensitive
# pass: do not highlight '%'
MirrorURL: http://mirror.centos.org/centos-%{OSVERSION}/%{OSVERSION}/os/$basearch/
 From: ubuntu:18.04 # pass: leading whitespace allowed

%setup
    touch /file1
touch ${SINGULARITY_ROOTFS}/file2 # pass: leading whitespace optional

%files
    /file1
    /file1 /opt

%environment
    export LISTEN_PORT=12345
    export LC_ALL=C

%runscript
    echo "Container was created $NOW"
    echo "Arguments received: $*"
    exec echo "$@"

%startscript
    nc -lp $LISTEN_PORT

%test
    grep -q NAME=\"Ubuntu\" /etc/os-release
    if [ $? -eq 0 ]; then
        echo "Container base is Ubuntu as expected."
    else
        echo "Container base is not Ubuntu."
    fi

%labels
    Author d@sylabs.io
    Version v0.0.1

%help
    This is a demo container used to illustrate a def file that uses all
    supported sections.

%post
    apt-get update && apt-get install -y netcat
    NOW=$((date % 1)) # pass: don't highlight '%'
    echo "export NOW=\"${NOW}\"" >> $SINGULARITY_ENVIRONMENT

---tokens---
'BoOtStRaP'   Keyword
':'           Text
' '           Text
'l'           Text
'i'           Text
'b'           Text
'r'           Text
'a'           Text
'r'           Text
'y'           Text
'  # pass: headers are case-insensitive\n' Comment

"# pass: do not highlight '%'\n" Comment

'MirrorURL'   Keyword
':'           Text
' '           Text
'h'           Text
't'           Text
't'           Text
'p'           Text
':'           Text
'/'           Text
'/'           Text
'm'           Text
'i'           Text
'r'           Text
'r'           Text
'o'           Text
'r'           Text
'.'           Text
'c'           Text
'e'           Text
'n'           Text
't'           Text
'o'           Text
's'           Text
'.'           Text
'o'           Text
'r'           Text
'g'           Text
'/'           Text
'c'           Text
'e'           Text
'n'           Text
't'           Text
'o'           Text
's'           Text
'-'           Text
'%'           Text
'{'           Text
'O'           Text
'S'           Text
'V'           Text
'E'           Text
'R'           Text
'S'           Text
'I'           Text
'O'           Text
'N'           Text
'}'           Text
'/'           Text
'%'           Text
'{'           Text
'O'           Text
'S'           Text
'V'           Text
'E'           Text
'R'           Text
'S'           Text
'I'           Text
'O'           Text
'N'           Text
'}'           Text
'/'           Text
'o'           Text
's'           Text
'/'           Text
'$'           Text
'b'           Text
'a'           Text
's'           Text
'e'           Text
'a'           Text
'r'           Text
'c'           Text
'h'           Text
'/'           Text
'\n'          Text

' '           Text
'From'        Keyword
':'           Text
' '           Text
'u'           Text
'b'           Text
'u'           Text
'n'           Text
't'           Text
'u'           Text
':'           Text
'18.04'       Literal.Number
' # pass: leading whitespace allowed\n' Comment

'\n'          Text

'%setup'      Generic.Heading
'\n    '      Text
'touch'       Text
' '           Text
'/file1'      Text
'\n'          Text

'touch'       Text
' '           Text
'${'          Literal.String.Interpol
'SINGULARITY_ROOTFS' Name.Variable
'}'           Literal.String.Interpol
'/file2'      Text
' '           Text
'# pass: leading whitespace optional\n' Comment.Single

'\n'          Text

'%files'      Generic.Heading
'\n    '      Text
'/file1'      Text
'\n    '      Text
'/file1'      Text
' '           Text
'/opt'        Text
'\n'          Text

'\n'          Text

'%environment' Generic.Heading
'\n    '      Text
'export'      Name.Builtin
' '           Text
'LISTEN_PORT' Name.Variable
'='           Operator
'12345'       Literal.Number
'\n    '      Text
'export'      Name.Builtin
' '           Text
'LC_ALL'      Name.Variable
'='           Operator
'C'           Text
'\n'          Text

'\n'          Text

'%runscript'  Generic.Heading
'\n    '      Text
'echo'        Name.Builtin
' '           Text
'"'           Literal.String.Double
'Container was created ' Literal.String.Double
'$NOW'        Name.Variable
'"'           Literal.String.Double
'\n    '      Text
'echo'        Name.Builtin
' '           Text
'"'           Literal.String.Double
'Arguments received: ' Literal.String.Double
'$*'          Name.Variable
'"'           Literal.String.Double
'\n    '      Text
'exec'        Name.Builtin
' '           Text
'echo'        Name.Builtin
' '           Text
'"'           Literal.String.Double
'$@'          Name.Variable
'"'           Literal.String.Double
'\n'          Text

'\n'          Text

'%startscript' Generic.Heading
'\n    '      Text
'nc'          Text
' '           Text
'-lp'         Text
' '           Text
'$LISTEN_PORT' Name.Variable
'\n'          Text

'\n'          Text

'%test'       Generic.Heading
'\n    '      Text
'grep'        Text
' '           Text
'-q'          Text
' '           Text
'NAME'        Name.Variable
'='           Operator
'\\"'         Literal.String.Escape
'Ubuntu'      Text
'\\"'         Literal.String.Escape
' '           Text
'/etc/os-release' Text
'\n    '      Text
'if'          Keyword
' '           Text
'['           Operator
' '           Text
'$?'          Name.Variable
' '           Text
'-eq'         Text
' '           Text
'0'           Literal.Number
' '           Text
']'           Operator
';'           Punctuation
' '           Text
'then'        Keyword
'\n        '  Text
'echo'        Name.Builtin
' '           Text
'"Container base is Ubuntu as expected."' Literal.String.Double
'\n    '      Text
'else'        Keyword
'\n        '  Text
'echo'        Name.Builtin
' '           Text
'"Container base is not Ubuntu."' Literal.String.Double
'\n    '      Text
'fi'          Keyword
'\n'          Text

'\n'          Text

'%labels'     Generic.Heading
'\n    '      Text
'Author'      Text
' '           Text
'd@sylabs.io' Text
'\n    '      Text
'Version'     Text
' '           Text
'v0.0.1'      Text
'\n'          Text

'\n'          Text

'%help'       Generic.Heading
'\n    '      Text
'This'        Text
' '           Text
'is'          Text
' '           Text
'a'           Text
' '           Text
'demo'        Text
' '           Text
'container'   Text
' '           Text
'used'        Text
' '           Text
'to'          Text
' '           Text
'illustrate'  Text
' '           Text
'a'           Text
' '           Text
'def'         Text
' '           Text
'file'        Text
' '           Text
'that'        Text
' '           Text
'uses'        Text
' '           Text
'all'         Text
'\n    '      Text
'supported'   Text
' '           Text
'sections.'   Text
'\n'          Text

'\n'          Text

'%post'       Generic.Heading
'\n    '      Text
'apt-get'     Text
' '           Text
'update'      Text
' '           Text
'&&'          Operator
' '           Text
'apt-get'     Text
' '           Text
'install'     Text
' '           Text
'-y'          Text
' '           Text
'netcat'      Text
'\n    '      Text
'NOW'         Name.Variable
'='           Operator
'$(('         Keyword
'date'        Text
' '           Text
'%'           Operator
' '           Text
'1'           Literal.Number
'))'          Keyword
' '           Text
"# pass: don't highlight '%'\n" Comment.Single

'    '        Text
'echo'        Name.Builtin
' '           Text
'"'           Literal.String.Double
'export NOW=\\"' Literal.String.Double
'${'          Literal.String.Interpol
'NOW'         Name.Variable
'}'           Literal.String.Interpol
'\\"'         Literal.String.Double
'"'           Literal.String.Double
' '           Text
'>>'          Text
' '           Text
'$SINGULARITY_ENVIRONMENT' Name.Variable
'\n'          Text