apache/hadoop · error · IOException

Illegal file pattern: An escaped character does not present

Error message

Illegal file pattern: An escaped character does not present for glob " + filePattern + " at " + i

What it means

Error "Illegal file pattern: An escaped character does not present for glob " + filePattern + " at " + i" thrown in apache/hadoop.

Source

Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/GlobExpander.java:108

    int leftmost = leftmostOuterCurlyContainingSlash(filePattern,
        filePatternWithOffset.offset);
    if (leftmost == -1) {
      return null;
    }
    int curlyOpen = 0;
    StringBuilder prefix = new StringBuilder(filePattern.substring(0, leftmost));
    StringBuilder suffix = new StringBuilder();
    List<String> alts = new ArrayList<String>();
    StringBuilder alt = new StringBuilder();
    StringBuilder cur = prefix;
    for (int i = leftmost; i < filePattern.length(); i++) {
      char c = filePattern.charAt(i);
      if (cur == suffix) {
        cur.append(c);
      } else if (c == '\\') {
        i++;
        if (i >= filePattern.length()) {
          throw new IOException("Illegal file pattern: "
              + "An escaped character does not present for glob "
              + filePattern + " at " + i);
        }
        c = filePattern.charAt(i);
        cur.append(c);
      } else if (c == '{') {
        if (curlyOpen++ == 0) {
          alt.setLength(0);
          cur = alt;
        } else {
          cur.append(c);
        }

      } else if (c == '}' && curlyOpen > 0) {
        if (--curlyOpen == 0) {
          alts.add(alt.toString());
          alt.setLength(0);
          cur = suffix;

View on GitHub (pinned to 2add963021)

Solutions

1. Remove the dangling backslash at the end of the glob pattern or escape a following character.
2. Validate the glob pattern before use.

When it happens

Trigger: Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/GlobExpander.java:108 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/4a55fe8c09473e93. Report an issue: GitHub.