Commit | Line | Data |
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249fb9ba AT |
1 | /* |
2 | * (c) 2019 Aaron Taylor <ataylor at subgeniuskitty dot com> | |
3 | * All rights reserved. | |
4 | */ | |
5 | ||
6 | #include <stdio.h> | |
7 | #include <stdlib.h> | |
8 | #include <unistd.h> | |
9 | #include <string.h> | |
10 | #include <errno.h> | |
11 | #include <getopt.h> | |
12 | #include <stdint.h> | |
13 | ||
14 | #define VERSION 1 | |
15 | ||
16 | void | |
17 | print_usage(char ** argv) | |
18 | { | |
19 | printf( "VVhitespace Interpreter v%d (www.subgeniuskitty.com)\n" | |
20 | "Usage: %s -i <file> -o <file>\n" | |
21 | " -h Help (prints this message)\n" | |
22 | " -i <file> Specify a pseudo-VVhitespace source file as input.\n" | |
23 | " -o <file> Specify location for VVhitespace output.\n" | |
24 | , VERSION, argv[0] | |
25 | ); | |
26 | } | |
27 | ||
f10da6e3 | 28 | /* Builds an ASCII string on the stack using VVS PUSH_IMMEDIATE commands. */ |
971552ff AT |
29 | /* The syntax: A"test" results in five PUSH_IMMEDIATE commands for the four */ |
30 | /* letters, and null-terminator. */ | |
b8b65c17 AT |
31 | /* Expects 'input' to present a double-quoted ('"') ASCII string. */ |
32 | /* The 'A' has already been chomped. */ | |
33 | void | |
34 | parse_ascii_string(FILE * input, FILE * output) | |
35 | { | |
36 | uint8_t temp_byte; | |
37 | fread(&temp_byte, 1, 1, input); | |
0e014963 AT |
38 | if (temp_byte != '"') { |
39 | /* Die here since we walk the string backward and look for '"' as a terminator. */ | |
40 | fprintf(stderr, "ERROR: Expected double-quote to begin string.\n"); | |
41 | exit(EXIT_FAILURE); | |
42 | } | |
b8b65c17 AT |
43 | |
44 | /* Put the letters on the stack in reverse. Don't forget to put a null-terminator first. */ | |
45 | for (fread(&temp_byte,1,1,input); temp_byte != '"'; fread(&temp_byte,1,1,input)) continue; | |
46 | temp_byte = '\0'; | |
47 | ||
48 | while (temp_byte != '"') { | |
49 | /* First, push three spaces to start a PUSH_IMMEDIATE command for a positive number. */ | |
50 | uint8_t temp_output = ' '; | |
51 | for(int i=0;i<3;i++) fwrite(&temp_output, 1, 1, output); | |
0e014963 | 52 | /* Second, push the ASCII character, 7 bits total, most significant bit first. */ |
b8b65c17 AT |
53 | /* Remember, [Tab]=1 and [Space]=0. */ |
54 | uint8_t index = 7; /* 7 bits needed per ASCII character. */ | |
55 | while (index) { | |
56 | ((temp_byte >> (index-1)) & 1) ? (temp_output = '\t') : (temp_output = ' '); | |
57 | fwrite(&temp_output, 1, 1, output); | |
58 | index--; | |
59 | } | |
60 | /* Third, close the number with a newline. */ | |
61 | temp_output = '\n'; | |
62 | fwrite(&temp_output, 1, 1, output); | |
63 | ||
64 | /* Read the next byte to prepare for the loop test. */ | |
65 | fseek(input, -2, SEEK_CUR); | |
66 | fread(&temp_byte, 1, 1, input); | |
67 | } | |
971552ff AT |
68 | |
69 | /* Advance the stream pointer to the end of the string before returning. */ | |
70 | for (fread(&temp_byte,1,1,input); temp_byte != '"'; fread(&temp_byte,1,1,input)) continue; | |
b8b65c17 AT |
71 | } |
72 | ||
249fb9ba AT |
73 | int |
74 | main(int argc, char ** argv) | |
75 | { | |
76 | /* | |
77 | * Process command line arguments | |
78 | */ | |
79 | int c; | |
80 | FILE * input = NULL, * output = NULL; | |
81 | while ((c = getopt(argc,argv,"i:o:h")) != -1) { | |
82 | switch (c) { | |
83 | case 'i': | |
84 | if ((input = fopen(optarg, "r")) == NULL) { | |
85 | fprintf(stderr, "ERROR: %s: %s\n", optarg, strerror(errno)); | |
86 | } | |
87 | break; | |
88 | case 'o': | |
89 | if ((output = fopen(optarg, "w+")) == NULL) { | |
90 | fprintf(stderr, "ERROR: %s: %s\n", optarg, strerror(errno)); | |
91 | } | |
92 | break; | |
93 | case 'h': | |
94 | print_usage(argv); | |
95 | exit(EXIT_SUCCESS); | |
96 | break; | |
97 | default: | |
98 | break; | |
99 | } | |
100 | } | |
101 | if (input == NULL) { | |
102 | fprintf(stderr, "ERROR: Must specify a pseudo-VVhitespace source file with -i flag.\n"); | |
103 | print_usage(argv); | |
104 | exit(EXIT_FAILURE); | |
105 | } | |
106 | if (output == NULL) { | |
107 | fprintf(stderr, "ERROR: Must specify destination for VVhitespace source file with -o flag.\n"); | |
108 | print_usage(argv); | |
109 | exit(EXIT_FAILURE); | |
110 | } | |
111 | ||
112 | /* | |
113 | * Main Loop | |
114 | */ | |
115 | uint8_t temp_byte; | |
116 | while (fread(&temp_byte, 1, 1, input)) { | |
117 | switch (temp_byte) { | |
118 | case 't': | |
119 | case 'T': | |
120 | temp_byte = '\t'; | |
121 | fwrite(&temp_byte, 1, 1, output); | |
122 | break; | |
123 | case 's': | |
124 | case 'S': | |
125 | temp_byte = ' '; | |
126 | fwrite(&temp_byte, 1, 1, output); | |
127 | break; | |
128 | case 'n': | |
129 | case 'N': | |
130 | temp_byte = '\n'; | |
131 | fwrite(&temp_byte, 1, 1, output); | |
132 | break; | |
133 | case 'v': | |
134 | case 'V': | |
135 | temp_byte = '\v'; | |
136 | fwrite(&temp_byte, 1, 1, output); | |
137 | break; | |
b8b65c17 AT |
138 | case 'a': |
139 | case 'A': | |
140 | parse_ascii_string(input, output); | |
141 | break; | |
249fb9ba AT |
142 | case '\n': |
143 | /* Intentionally empty */ | |
144 | break; | |
145 | default: | |
b8b65c17 | 146 | /* The first non-[tTsSnNvVaA] character begins a comment lasting until end of line. */ |
249fb9ba AT |
147 | while (fread(&temp_byte, 1, 1, input)) { |
148 | if (temp_byte == '\n') break; | |
149 | } | |
150 | break; | |
151 | } | |
152 | } | |
153 | ||
154 | /* | |
155 | * Cleanup and exit | |
156 | */ | |
157 | fclose(input); | |
158 | fclose(output); | |
159 | ||
249fb9ba AT |
160 | exit(EXIT_SUCCESS); |
161 | } |