How to escape special chars - (for example, / \ ; : " | ? ' < > * ).

Hi. Refer the code below:

if(
  a!isNullOrEmpty(ri!input),
  null,
  regexreplaceall(
    pattern: "[\\/;:""|?'<>*\]\[]",
    searchString: trim(ri!input),
    replacementString: ""
  )
)

that did not work - need to show the validation message on the screen for fileupload component 

a!fileUploadField(
label: "Upload File",
target: cons!FOLDER_CONSTANT,
value: ri!uploadedFile,
saveInto: ri!uploadedFile,

validations: if(
and(
not(isnull(ri!uploadedFile)),
length(stripwith(ri!uploadedFile.name, "\ / ; : "" | ? ' < > *")) <> length(ri!uploadedFile.name)
),
"Filename cannot contain special characters (for example, / \ ; : " | ? ' < > * )."
null
)
)

that did not work - need to show the validation message on the screen for fileupload component 

a!fileUploadField(
label: "Upload File",
target: cons!FOLDER_CONSTANT,
value: ri!uploadedFile,
saveInto: ri!uploadedFile,

validations: if(
and(
not(isnull(ri!uploadedFile)),
length(stripwith(ri!uploadedFile.name, "\ / ; : "" | ? ' < > *")) <> length(ri!uploadedFile.name)
),
"Filename cannot contain special characters (for example, / \ ; : " | ? ' < > * )."
null
)
)

Try this:

a!localVariables(
  local!file,
  {
    a!fileUploadField(
      label: "Upload File",
      target: cons!FOLDER_CONSTANT,
      value: local!file,
      saveInto: local!file,
      validations: {
        if(
          a!isNullOrEmpty(fv!files),
          null,
          if(
            regexmatch(
              pattern: "[\\/;:""|?'<>*\]\[]",
              searchString: trim(fv!files.name),
            ),
            "Filename cannot contain special characters (for example, / \ ; : "" | ? ' < > * ).",
            null
          )
        )
      },
      maxSelections: 1
    )
  }
)