Programming Internet Email by David Wood

ASCII is the American Standard Code for Information Interchange, as established by the United States of America Standards Institute (USASI) way back in 1968. It is a 7-bit code, representing 2 to the seventh power possible 7-bit combinations as 128 characters.

Many other character sets use US-ASCII as their lower half, defining an 8-bit code. The default character set for the Linux operating system is the 8-bit ISO 8859-1 code is one of these.

The following table shows US-ASCII characters and their octal, decimal, and hexa-decimal equivalents.

Oct Dec Hex Char Oct Dec Hex Char ---------------- ---------------- 000 0 00 NUL 025 21 15 NAK 001 1 01 SOH 026 22 16 SYN 002 2 02 STX 027 23 17 ETB 003 3 03 ETX 030 24 18 CAN 004 4 04 EOT 031 25 19 EM 005 5 05 ENQ 032 26 lA SUB 006 6 06 ACK 033 27 lB ESC 007 7 07 BEL 034 28 lC FS 010 8 08 BS 035 29 lD GS 011 9 09 HT 036 30 lE RS 012 10 0A LF 037 31 IF US 013 11 0B VT 040 32 20 SPACE 014 12 0C FF 041 33 21 ! 015 13 0D CR 042 34 22 " 016 14 0E SO 043 35 23 # 017 15 0F SI 044 36 24 $ 020 16 10 DLE 045 37 25 % 021 17 11 DCl 046 38 26 & 022 18 12 DC2 047 39 27 ' 023 19 13 DC3 050 40 28 ( 024 20 14 DC4 051 41 29 ) 052 42 2A * 125 85 55 U 053 43 2B + 126 86 56 V 054 44 2C , 127 87 57 W 055 45 2D - 130 88 58 X 056 46 2E . 131 89 59 Y 057 47 2F / 132 90 5A Z 060 48 30 0 133 91 5B [ 061 49 31 1 134 92 5C \ 062 50 32 2 135 93 5D ] 063 51 33 3 136 94 5E ^ 064 52 34 4 137 95 5F _ 065 53 35 5 140 96 60 ̀ 066 54 36 6 141 97 61 a 067 55 37 ...