Version 1 of the C program that can print its source code

Version 1

 
# Include <stdio. h>IntMain (){Char* P ="# Include <stdio. h> % C int main () {char * P = % C % S % C; printf (p, 10, 34, p, 34 );}"; Printf (p,10,34, P,34);}
 

Rating:

This implementation is very subtle. The first p transmits the current string as the printf format string, and uses the following parameters to replace the placeholder in the format string (% C,% C % S % C) To generate a new string, the first% CReplaced with a carriage return (ASCII value of 10)% C % S % CIs replaced:"# Include <stdio. h> % C int main () {char * P = % C % S % C; printf (p, 10, 34, p, 34 );}"(The ASCII code value of 34 is double quotation marks,% SThen replace it with P. printf copies the replaced string to the new memory block without modifying the format string pointed to by P)

 

Note:

In Linux, there is a command line tool for viewing the ASCII code value table. In ubuntu, you can install the ASCII code through sudo apt-Get install. Start the command:

$ ASCII

 Dec hex dec hex 0 00 NUL 16 10 DLE 32 20 30 30 0 64 40 @ 80 50 p 96 60 '112 70 P 1 01 Soh 17 11 DC1 33 21! 49 31 1 65 41 A 81 51 Q 97 61 A 113 71 Q 2 02 STX 18 12 DC2 34 22" 50 32 2 66 42 B 82 52 r 98 62 B 114 72 R 3 03 etx 19 13 DC3 35 23 #51 33 3 67 43 C 83 53 s 99 63 C 115 73 s 4 04 EOT 20 14 dc4 36 24 $52 34 4 68 44 d 84 54 t 100 64 d 116 74 T 5 05 Enq 21 15 Nak 37 25% 53 35 5 69 45 E 85 55 U 101 65 E 117 75 U 6 06 ack 22 16 SYN 38 26 & 54 36 6 70 46 F 86 56 v 102 66 F 118 76 V 7 07 Bel 23 17 etb 39 27 '55 37 7 71 47g 87 57 W 103 67g 119 77 W 8 08 BS 24 18 can 40 28 (56 38 8 72 48 h 88 58x104 68 H 120 78X9 09 HT 25 19 em 41 29) 57 39 9 73 49 I 89 59 y 105 69 I 121 79 y10 0a lf 26 1A sub 42 2a * 58 3A: 74 4A J 90 5A Z 106 6a J 122 7A Z 11 0b VT 27 1B ESC 43 2B + 59 3B; 75 4B K 91 5B [107 6B K 123 7b {12 0C FF 28 1C FS 44 2C, 60 3C <76 4C l 92 5C \ 108 6C L 124 7C | 13 0d Cr 29 1D GS 45 2D-61 3D = 77 4D M 93 5D] 109 6D M 125 7d} 14 0e so 30 1E Rs 46 2E. 62 3E> 78 4E N 94 5E ^ 110 6e n 126 7E ~ 15 0f Si 31 1f us 47 2f/63 3f? 79 4f o 95 5f_ 111 6f o 127 7f del