Old text has ‹ where French words should have ï

Byte 139 is ï in code page 437 and ‹ in Windows-1252, so a DOS file decoded as Windows turns naïf into na‹f and maïs into ma‹s. Since ‹ passes for punctuation, the damage is easy to overlook. In Ruby, `File.read('old.txt', encoding: 'IBM437:UTF-8')` reads the file and converts it in one step.

ASCII 139

Single left angle quoteLowercase i with umlaut

ASCII 139 is ‹ on Windows and ï in old DOS.

‹ (Single Left Angle Quote) is byte 139 in Windows-1252, Unicode U+2039. It's the single form of the guillemet «, and Swiss typography uses it for a quote inside a quote: «Er sagte ‹nein›». German print turns the pair around so they point inward, ›so‹. On the web you'll also find it as a pagination arrow, as in ‹ Prev. A screen reader treats it as punctuation there, so give the link a text label or an aria-label. It isn't a less-than sign either: ‹ in place of < won't open an HTML tag or compare anything. Its partner › is byte 155. In UTF-8 it's E2 80 B9, garbled as â€¹. The HTML entity is &lsaquo;.

ï (Small I with Diaeresis) is byte 139 in code page 437, the original IBM PC character set, and maps to Unicode U+00EF. Windows-1252 has the single left angle quote ‹ at 139, so DOS text read as Windows-1252 turns naïve into na‹ve. Code page 850 kept ï at 139 too.

PunctuationLatin Letter

Technical Details

Code Example

</>

#include <stdio.h>

int main(void) {
    /* On Windows (code page 1252) byte 139 is ‹.
       Modern terminals expect UTF-8, so print the code point, not the byte. */
    printf("\u2039\n");   /* UTF-8: E2 80 B9 */

    unsigned char b = 139;         /* the raw Windows-1252 byte */
    printf("%d 0x%02X\n", b, b);    /* 139 0x8B */
    return 0;
}

Code Example

</>

#include <stdio.h>

int main(void) {
    /* Byte 139 is ï only on a console using code page 437
       (chcp 437 on Windows, or DOSBox). On a UTF-8 terminal the
       lone byte 0x8B is invalid and prints as garbage, often �. */
    putchar(139);

    /* char is signed on x86, so a plain char holding 0x8B is -117.
       Use unsigned char when you compare or index by byte value. */
    char c = (char)139;
    unsigned char u = 139;
    printf("\n%d %d\n", c, u);   /* -117 139 */

    /* Portable: print the Unicode character as UTF-8 instead. */
    printf("\u00EF\n");          /* C3 AF */
    return 0;
}

How to Type It

Windows: Hold Alt and type 0139 on the numeric keypad, with Num Lock on. The leading zero picks the Windows code page. No numeric keypad? In Word, type 2039 and press Alt+X.
Mac: Press Option+Shift+3.
Linux: In GNOME, or any desktop running IBus, press Ctrl+Shift+U, type 2039, then Space. With a Compose key set up, press Compose, period, less-than.
Phone: Tap the character at the top of this page to copy it.

How to Type It

Windows: Hold Alt and type 139 on the numeric keypad, with no leading zero. Windows reads it as a DOS code and inserts ï.

ï is also ASCII 239 on Windows, which has the full guide.

Frequently Asked Questions

Byte 139 is ï in code page 437 and ‹ in Windows-1252, so a DOS file decoded as Windows turns naïf into na‹f and maïs into ma‹s. Since ‹ passes for punctuation, the damage is easy to overlook. In Ruby, `File.read('old.txt', encoding: 'IBM437:UTF-8')` reads the file and converts it in one step.

Frequently Asked Questions

Byte 139 is ï in code page 437 and ‹ in Windows-1252, so a DOS file decoded as Windows turns naïf into na‹f and maïs into ma‹s. Since ‹ passes for punctuation, the damage is easy to overlook. In Ruby, `File.read('old.txt', encoding: 'IBM437:UTF-8')` reads the file and converts it in one step.

ASCII 139

Single left angle quoteLowercase i with umlaut

ASCII 139 is ‹ on Windows and ï in old DOS.

Punctuation

Latin Letter

#include <stdio.h>

int main(void) {

/* On Windows (code page 1252) byte 139 is ‹.

Modern terminals expect UTF-8, so print the code point, not the byte. */

printf("\u2039\n"); /* UTF-8: E2 80 B9 */

unsigned char b = 139; /* the raw Windows-1252 byte */

printf("%d 0x%02X\n", b, b); /* 139 0x8B */

return 0;

}

#include <stdio.h>

int main(void) {

/* Byte 139 is ï only on a console using code page 437

(chcp 437 on Windows, or DOSBox). On a UTF-8 terminal the

lone byte 0x8B is invalid and prints as garbage, often �. */

putchar(139);

/* char is signed on x86, so a plain char holding 0x8B is -117.

Use unsigned char when you compare or index by byte value. */

char c = (char)139;

unsigned char u = 139;

printf("\n%d %d\n", c, u); /* -117 139 */

/* Portable: print the Unicode character as UTF-8 instead. */

printf("\u00EF\n"); /* C3 AF */

return 0;

}