notwa/gists
1
0
Fork 0
Code Issues Pull requests Releases Wiki Activity

Merge remote-tracking branch 'kyaa/master'

Browse source
This commit is contained in:
Connor Olding 2018-10-11 16:45:32 +02:00
commit b9960ee594
3 changed files with 484 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

113
kyaa.h Normal file
View file

@ -0,0 +1,113 @@
/* kyaa.h - macro hacks for handling main() arguments
This is free and unencumbered software released into the public domain.
Refer to kyaa.md for documentation.
*/
#pragma once
#ifndef KYAA_OKAY
#define KYAA_OKAY 0
#endif
#ifndef KYAA_ERROR
#define KYAA_ERROR 1
#endif
#ifndef KYAA_ITER
#define KYAA_ITER i
#endif
#define KYAA_SETUP \
/* sanity checks */ \
if (argc <= 0 || argv == NULL || argv[0] == NULL) { \
fprintf(stderr, "You've met with a terrible fate.\n"); \
return KYAA_ERROR; \
} \
char *kyaa_name = argv[0]; \
bool kyaa_read_stdin = false; \
char kyaa_flag = '\0'; \
bool kyaa_keep_parsing = true; \
bool kyaa_parse_next = false; \
#define KYAA_LOOP \
KYAA_SETUP \
for (int KYAA_ITER = 1; KYAA_ITER < argc; KYAA_ITER++) \
#define KYAA_BEGIN \
char *kyaa_arg = argv[KYAA_ITER]; \
if (kyaa_keep_parsing && (kyaa_parse_next || kyaa_arg[0] == '-')) { \
if (!kyaa_parse_next && kyaa_arg[1] == '-' && kyaa_arg[2] == '\0') { \
kyaa_keep_parsing = false; \
continue; \
} \
if (!kyaa_parse_next && kyaa_arg[1] == '\0') { \
kyaa_read_stdin = true; \
} else { \
/* case: kyaa_parse_next: arg is at least 1 char initialized. */ \
/* case: !kyaa_parse_next: arg is at least 3 chars initialized. */ \
char *kyaa_etc = kyaa_parse_next ? kyaa_arg : kyaa_arg + 2; \
bool kyaa_no_more = false; \
bool kyaa_helping = false; \
bool kyaa_any = false; \
if (!kyaa_parse_next && kyaa_arg[1] != '-') { \
kyaa_flag = kyaa_arg[1]; \
kyaa_no_more = kyaa_arg[2] == '\0'; \
} \
if (kyaa_flag == 'h' || !strcmp(kyaa_arg, "--help")) { \
printf("usage:\n"); \
kyaa_helping = true; \
} \
if (0) { \
#define KYAA_END \
} \
if (!kyaa_any && !kyaa_helping) { \
if (kyaa_flag) { \
fprintf(stderr, "unknown flag: -%c\n", kyaa_flag); \
} else { \
fprintf(stderr, "unknown flag: %s\n", kyaa_arg); \
} \
return KYAA_ERROR; \
} \
if (kyaa_helping) { \
return KYAA_OKAY; \
} \
kyaa_parse_next = false; \
kyaa_flag = '\0'; \
continue; \
} \
} \
#define KYAA_DESCRIBE(c, name, description) \
printf(" -%c --%s\n%s\n", c, name, description) \
#define KYAA_FLAG(c, name, description) \
} \
if (kyaa_helping) { \
KYAA_DESCRIBE(c, name, description); \
} else if (kyaa_flag == c || !strcmp(kyaa_arg, "--"name)) { \
kyaa_flag = c; \
kyaa_any = true; \
#define KYAA_FLAG_ARG(c, name, description) \
} \
if (kyaa_helping) { \
KYAA_DESCRIBE(c, name, description); \
} else if (kyaa_flag == c || !strcmp(kyaa_arg, "--"name)) { \
if (kyaa_no_more || kyaa_flag != c) { \
kyaa_parse_next = true; \
if (KYAA_ITER + 1 == argc || argv[KYAA_ITER + 1][0] == '\0') { \
fprintf(stderr, "expected an argument for --%s (-%c)\n", name, c); \
return KYAA_ERROR; \
} \
kyaa_flag = c; \
continue; \
} \
kyaa_flag = c; \
kyaa_any = true; \
#define KYAA_HELP(description) \
} \
if (kyaa_helping) { \
if (description != NULL) { \
printf("%s\n", description); \
} \

160
kyaa.md Normal file
View file

@ -0,0 +1,160 @@
# kyaa
super hacky macro hacks for parsing arguments in C.
## prerequisites
C99 or greater.
standard library headers:
* `stdbool.h`
* `stdio.h`
* `string.h`
in addition, `kyaa_extra.h` requires `limits.h`,
or at least `LONG_MIN` to be defined.
## tutorial
ensure `argc` and `argv` are defined.
kyaa doesn't actually care if it's in `main` or not.
iterate over the arguments with `KYAA_LOOP`:
```c
int main(int argc, char *argv[]) {
KYAA_LOOP {
// KYAA_ITER, kyaa_name, kyaa_read_stdin, and kyaa_flag are exposed here.
// [other code goes here]
}
return 0;
}
```
use `KYAA_BEGIN` and `KYAA_END` to begin parsing arguments.
put unrelated code above `KYAA_BEGIN` or below `KYAA_END`, but not within:
```c
KYAA_LOOP {
// [other code goes here]
KYAA_BEGIN
// kyaa_arg and kyaa_etc are exposed here.
// [kyaa code goes here]
KYAA_END
// [other code goes here]
}
```
use `KYAA_FLAG` for defining flags that don't take an argument,
and `KYAA_FLAG_ARG` or `KYAA_FLAG_LONG` for flags that do:
```c
bool use_feature = false;
char *log_fn = "logs.txt";
long my_var = 0;
KYAA_LOOP {
// [other code goes here]
KYAA_BEGIN
// arguments: short flag, long flag, help description
KYAA_FLAG("-x", "--enable-feature",
" enable some feature")
use_feature = true;
// same arguments, but kyaa_etc contains the relevant string.
KYAA_FLAG_ARG("-l", "--log-file",
" use a given filename for the log file")
log_fn = kyaa_etc;
// same arguments, kyaa_etc is set, but kyaa_flag_arg is also set.
KYAA_FLAG_LONG("-v", "--var",
" set an integer variable\n"
" default: 0")
my_var = kyaa_flag_arg;
KYAA_END
// [other code goes here]
}
```
kyaa secretly wraps flag handling in if/else statements with {} blocks.
do not confuse it for a switch/case method.
kyaa handles `-h` and `--help` for printing help text.
additional help text may be defined using `KYAA_HELP`:
```c
KYAA_LOOP {
KYAA_BEGIN
KYAA_HELP(
" {files...}\n"
" do things with files.")
KYAA_END
do_stuff(kyaa_arg);
}
```
kyaa interprets an argument of `-` as a request to enable reading from stdin:
`kyaa_read_stdin` is set to true.
arguments may be passed in three ways, consider:
* `-v42`
* `-v 42`
* `--var 42`
kyaa returns `KYAA_OKAY` when `-h` or `--help` is given,
and `KYAA_ERROR` in the event of invalid flags, missing arguments,
or invalid numbers (`KYAA_FLAG_LONG`).
kyaa uses `continue` for handling arguments.
kyaa prints error messages to `stderr`, and help text to `stdout`.
`KYAA_ITER` may be redefined to avoid name collisions.
## TODO
* support `--var=42` argument style
* fix overlapping names, e.g. `KYAA_FLAG` vs `kyaa_flag`, `KYAA_FLAG_ARG` vs `kyaa_flag_arg`, etc.
* maybe pass `argc`/`argv` manually?
## API
### kyaa.h
return type or type | name | arguments or default value
--- | --- | ---
define | KYAA\_OKAY | 0
define | KYAA\_ERROR | 1
define | KYAA\_ITER | i
||
macro | KYAA\_SETUP | *none*
macro | KYAA\_LOOP | *none*
macro | KYAA\_BEGIN | *none*
macro | KYAA\_END | *none*
macro | KYAA\_DESCRIBE | c, name, description
macro | KYAA\_FLAG | c, name, description
macro | KYAA\_FLAG\_ARG | c, name, description
macro | KYAA\_HELP | description
||
`char *` | kyaa\_name | *n/a*
`bool` | kyaa\_read\_stdin | *n/a*
`char *` | kyaa\_arg | *n/a*
|| **internal use** ||
`char` | kyaa\_flag | *n/a*
`bool` | kyaa\_keep\_parsing | *n/a*
`bool` | kyaa\_parse\_next | *n/a*
`bool` | kyaa\_no\_more | *n/a*
`bool` | kyaa\_helping | *n/a*
`bool` | kyaa\_any | *n/a*
### kyaa\_extra.h
return value or type | name | arguments or default value
--- | --- | ---
macro | KYAA\_FLAG\_LONG | c, name, description
||
`char *` | kyaa\_flag\_arg | *n/a*
||
`char *` | kyaa\_skip\_spaces | `char *` str
`const char *` | kyaa\_str\_to\_long | `char *` str, `long *` p\_out

211
kyaa_extra.h Normal file
View file

@ -0,0 +1,211 @@
/* kyaa_extra.h - extensions to kyaa for parsing arguments.
This is free and unencumbered software released into the public domain.
Refer to kyaa.md for documentation.
*/
static char *kyaa_skip_spaces(char *str) {
/* iterates str to first non-space character according to the C locale */
while (*str != '\0') {
switch (*str) {
case ' ':
case '\f':
case '\n':
case '\r':
case '\t':
case '\v': { str++; } break;
default: return str;
}
}
return str;
}
static const char *kyaa__base_2(char **p_str, long *p_out) {
char *str = *p_str;
long out = *p_out;
for (char c; (c = *str) != '\0'; str++) {
switch (c) {
case '0': case '1': {
long digit = (long)(c - '0');
if (out < (LONG_MIN + digit) / 2) {
return "out of range for long integer";
}
out = out * 2 - digit;
} break;
case '2': case '3': case '4': case '5':
case '6': case '7': case '8': case '9':
case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
case '.': return "invalid character for base 2 integer";
default: goto exit;
}
}
exit:
*p_str = str;
*p_out = out;
return NULL;
}
static const char *kyaa__base_8(char **p_str, long *p_out) {
char *str = *p_str;
long out = *p_out;
for (char c; (c = *str) != '\0'; str++) {
switch (c) {
case '0': case '1': case '2': case '3':
case '4': case '5': case '6': case '7': {
long digit = (long)(c - '0');
if (out < (LONG_MIN + digit) / 8) {
return "out of range for long integer";
}
out = out * 8 - digit;
} break;
case '8': case '9':
case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
case '.': return "invalid character for base 8 integer";
default: goto exit;
}
}
exit:
*p_str = str;
*p_out = out;
return NULL;
}
static const char *kyaa__base_10(char **p_str, long *p_out) {
char *str = *p_str;
long out = *p_out;
for (char c; (c = *str) != '\0'; str++) {
switch (c) {
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9': {
long digit = (long)(c - '0');
if (out < (LONG_MIN + digit) / 10) {
return "out of range for long integer";
}
out = out * 10 - digit;
} break;
case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
case '.': return "invalid character for base 10 integer";
default: goto exit;
}
}
exit:
*p_str = str;
*p_out = out;
return NULL;
}
static const char *kyaa__base_16(char **p_str, long *p_out) {
char *str = *p_str;
long out = *p_out;
for (char c; (c = *str) != '\0'; str++) {
switch (c) {
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9': {
long digit = (long)(c - '0');
if (out < (LONG_MIN + digit) / 16) {
return "out of range for long integer";
}
out = out * 16 - digit;
} break;
case 'A': case 'B': case 'C': case 'D': case 'E': case 'F': {
long digit = (long)(c - 'A') + 10;
if (out < (LONG_MIN + digit) / 16) {
return "out of range for long integer";
}
out = out * 16 - digit;
} break;
case 'a': case 'b': case 'c': case 'd': case 'e': case 'f': {
long digit = (long)(c - 'a') + 10;
if (out < (LONG_MIN + digit) / 16) {
return "out of range for long integer";
}
out = out * 16 - digit;
} break;
case '.': return "invalid character for base 16 integer";
default: goto exit;
}
}
exit:
*p_str = str;
*p_out = out;
return NULL;
}
static const char *kyaa_str_to_long(char *str, long *p_out) {
/* returns error message or NULL */
long out = 0;
int base = 10;
bool negated = false;
str = kyaa_skip_spaces(str);
switch (*str) {
case '-': { negated = true; str++; } break;
case '+': { str++; } break;
default: break;
}
switch (*str) {
case '#': { base = 10; str++; } break;
case '$': { base = 8; str++; } break;
case '%': { base = 2; str++; } break;
case '0': { base = -1; str++; } break;
default: break;
}
if (base == -1) {
switch (*str) {
case '\0': { *p_out = 0; } return NULL;
case 'b': { base = 2; str++; } break;
case 'h': { base = 16; str++; } break;
case 'o': { base = 8; str++; } break;
case 'x': { base = 16; str++; } break;
default: { base = 8; } break;
}
}
if (*str == '\0') return "no number given";
// NOTE: we actually subtract each digit from the result instead of summing.
// this lets us represent LONG_MIN without overflowing.
const char *err;
switch (base) {
case 2: { err = kyaa__base_2( &str, &out); } break;
case 8: { err = kyaa__base_8( &str, &out); } break;
case 10: { err = kyaa__base_10(&str, &out); } break;
case 16: { err = kyaa__base_16(&str, &out); } break;
default: return "internal error";
}
if (err != NULL) return err;
str = kyaa_skip_spaces(str);
if (*str != '\0') return "unexpected character";
// NOTE: out is negative here; see above comment.
// assuming two's complement
if (!negated && out == LONG_MIN) return "out of range for long integer";
*p_out = negated ? out : -out;
return NULL;
}
#define KYAA_FLAG_LONG(c, name, description) \
KYAA_FLAG_ARG(c, name, description) \
long kyaa_flag_arg; \
const char *err = kyaa_str_to_long(kyaa_etc, &kyaa_flag_arg); \
if (err) { \
fprintf(stderr, "%s\n", err); \
return KYAA_ERROR; \
} \