method

extname

v1_9_1_378 - Show latest stable - 1 note - Class: File

extname(p1) public

Returns the extension (the portion of file name in path after the period).

File.extname("test.rb")         #=> ".rb"
File.extname("a/b/d/test.rb")   #=> ".rb"
File.extname("test")            #=> ""
File.extname(".profile")        #=> ""

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static VALUE
rb_file_s_extname(VALUE klass, VALUE fname)
{
    const char *name, *p, *e;
    VALUE extname;

    FilePathStringValue(fname);
    name = StringValueCStr(fname);
    p = strrdirsep(name);       /* get the last path component */
    if (!p)
        p = name;
    else
        name = ++p;

    e = 0;
    while (*p && *p == '.') p++;
    while (*p) {
        if (*p == '.' || istrailinggarbage(*p)) {
#if USE_NTFS
            const char *last = p++, *dot = last;
            while (istrailinggarbage(*p)) {
                if (*p == '.') dot = p;
                p++;
            }
            if (!*p || *p == ':') {
                p = last;
                break;
            }
            if (*last == '.' || dot > last) e = dot;
            continue;
#else
            e = p;       /* get the last dot of the last component */
#endif
        }
#if USE_NTFS
        else if (*p == ':') {
            break;
        }
#endif
        else if (isdirsep(*p))
            break;
        p = CharNext(p);
    }
    if (!e || e == name || e+1 == p)    /* no dot, or the only dot is first or end? */
        return rb_str_new(0, 0);
    extname = rb_str_new(e, p - e);     /* keep the dot, too! */
    rb_enc_copy(extname, fname);
    OBJ_INFECT(extname, fname);
    return extname;
}

January 27, 2010

1 thank

File name without the extension

To get the file name without the extension you can use File.extname in combination with File.basename

File.basename("test.rb", File.extname("test.rb"))             #=> "test"
File.basename("a/b/d/test.rb", File.extname("a/b/d/test.rb")) #=> "test"
File.basename("test", File.extname("test"))                   #=> "test"
File.basename(".profile", File.extname(".profile"))           #=> ".profile"

extname

Related methods

File name without the extension