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- /* bake.c - Ever burned a cake?
- * Copyright 2023 Emil Williams
- *
- * Licensed under the GNU Public License version 3 only, see LICENSE.
- *
- * @BAKE cc -std=c99 -O2 $@ -o $* $+ # @STOP
- */
-
- #define _POSIX_C_SOURCE 200809L
-
- #include <assert.h>
- #include <ctype.h>
- #include <errno.h>
- #include <fcntl.h>
- #include <locale.h>
- #include <stdarg.h>
- #include <stddef.h>
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.h>
- #include <sys/mman.h>
- #include <sys/stat.h>
- #include <sys/wait.h>
- #include <unistd.h>
-
- #include "config.h"
-
- #define HELP \
- BOLD "[option] target-file" RESET " [" GREEN "arguments" RESET " ...]\n" \
- "Use the format `" BOLD "@BAKE" RESET " cmd ...' within the target-file, this will execute the\n" \
- "rest of line, or if found within the file, until the " BOLD "@STOP" RESET " marker.\n" \
-
- #define DESC \
- "Options [Must always be first]\n" \
- "\t" DIM "-h --help" RESET", " BOLD "-n --dry-run\n" RESET \
- "Expansions\n" \
- "\t" YELLOW "$@" RESET " returns target-file (abc.x.txt)\n" \
- "\t" YELLOW "$*" RESET " returns target-file without suffix (^-> abc.x)\n" \
- "\t" YELLOW "$+" RESET " returns " GREEN "arguments" RESET "\n"
-
- typedef struct {
- size_t len;
- char * buf;
- } string_t;
-
- typedef string_t map_t;
-
- static string_t START = { 5, "@BAKE" };
- static string_t STOP = { 5, "@STOP" };
-
- /*** Utility functions ***/
-
- #define strneq(a,b,n) (!strncmp(a,b,n))
- #define streq(a,b) (!strcmp(a,b))
-
- static void
- swap(char * a, char * b) {
- *a ^= *b;
- *b ^= *a;
- *a ^= *b;
- }
-
- static char *
- find(string_t x, char * buf, char * end) {
- for (; (buf < end) && x.len < (size_t)(end - buf); ++buf) {
- if (!strncmp(buf, x.buf, x.len))
- { return buf; }
- }
- return NULL;
- }
-
- static void
- insert(char * str, size_t slen, char * new, size_t len, size_t shift) {
- memmove(str + len, str + shift, slen - len - shift);
- memcpy(str, new, len);
- }
-
- /*** g_short, g_all Functions ***/
-
- #define GLOBALS_COUNT 3
-
- static string_t globals[GLOBALS_COUNT];
-
- #define g_filename globals[0]
- #define g_short globals[1]
- #define g_all globals[2]
-
- static string_t
- shorten(string_t s) {
- size_t i, last = 0, len = s.len;
- char * sh, * fn = s.buf;
- sh = malloc(len);
- if (sh) {
- for (i = 0; i < len; ++i) {
- if (fn[i] == '.') { last = i; }
- }
- last = last ? last : i;
- strncpy(sh, fn, last);
- sh[last] = '\0';
- }
- return (string_t) { last, sh ? sh : calloc(0,0) };
- }
-
- static string_t
- all_args(int argc, char ** argv) {
- char * all = NULL;
- size_t len = 0;
- if (argc > 2) {
- int i;
- len = (size_t) argc;
-
- for (i = 2; i < argc; ++i)
- { len += strlen(argv[i]); }
-
- all = malloc(len);
- if (all) {
- all[len - 1] = '\0';
- for (len = 0, i = 2; i < argc; ++i) {
- strcpy(all + len, argv[i]);
- len += strlen(argv[i]) + 1;
- if (i + 1 < argc) { all[len - 1] = ' '; }
- }
- }
- }
- return (string_t) { len, all ? all : calloc(0,0) };
- }
-
- #if 0
- static string_t
- all_args(int argc, char ** argv) {
- string_t s = (string_t) { 0, NULL };
- if (argc > 2) {
- size_t i;
- for (i = (size_t) argc; i > 2; --i) {
- s.len += strlen(argv[i]) + 1;
- }
- s.buf = malloc(s.len + (size_t) argc);
- if (s.buf) {
- size_t len;
- s.buf[s.len - 1] = '\0';
- for (len = 0, i = (size_t) argc; i > 2; --i) {
- strcpy(s.buf + len, argv[i]);
- len += strlen(argv[i]) + 1;
- s.buf[len - 1] = ' ';
- }
- }
- }
- return s;
- }
- #endif
-
- /*** Map ***/
-
- static map_t
- map(char * fn) {
- struct stat s;
- int fd;
- map_t m = (map_t) {0};
- fd = open(fn, O_RDONLY);
- if (fd != -1) {
- if (!fstat(fd,&s)
- && s.st_mode & S_IFREG
- && s.st_size) {
- m.len = (size_t) s.st_size;
- m.buf = (char *) mmap(NULL, m.len, PROT_READ, MAP_SHARED, fd, 0);
- }
- close(fd);
- }
- return m;
- }
-
- /*** Important Functions ***/
-
- static string_t
- find_region(map_t m, string_t startsym, string_t stopsym) {
- extern char * strndup(const char * s, size_t n); /* for splint */
- char * buf = NULL, * start, * stop;
- size_t len;
-
- start = find(startsym, m.buf, m.buf + m.len);
-
- if (start) {
- start += startsym.len;
-
- #ifdef REQUIRE_SPACE
- if (!isspace(*start)) {
- fprintf(stderr, RED "%s" RESET ": Found start without suffix spacing.\n", g_filename.buf);
- return (string_t) { 0 , buf };
- }
- #endif /* REQUIRE_SPACE */
-
- stop = find(stopsym, start, start + m.len - (start - m.buf));
-
- if (!stop) {
- stop = start;
- while (*stop && *stop != '\n') {
- if (stop[0] == '\\'
- && stop[1] == '\n') { stop += 2; }
- ++stop;
- }
- }
-
- if (stop)
- {
- len = (size_t) (stop - m.buf) - (start - m.buf);
- buf = strndup(start, len);
- }
- }
- return (string_t) { len, buf };
- }
-
- static string_t
- file_find_region(char * fn, string_t start, string_t stop) {
- string_t s = { 0, NULL };
- map_t m = map(fn);
- if (m.buf) {
- s = find_region(m, start, stop);
- munmap(m.buf, m.len);
- }
- return s;
- }
-
- static int
- root(string_t s) {
- char x[1] = {'\0'};
- char * root = s.buf;
- size_t len = s.len;
- int ret;
-
- while (len && root[len] != '/')
- { --len; }
-
- if (!len) { return 0; }
-
- swap(root + len, x);
- ret = chdir(root);
- swap(root + len, x);
-
- /* *rootp += len + 1; */
- return ret;
- }
-
- #define ARRLEN(x) (sizeof(x) / sizeof(x[0]))
-
- static string_t
- expand(string_t s) {
- enum {
- MACRO_FILENAME = 0,
- MACRO_SHORT = 1,
- MACRO_ARGS = 2,
- };
-
- string_t macro[] = {
- [MACRO_FILENAME] = { 2, "$@" },
- [MACRO_SHORT ] = { 2, "$*" },
- [MACRO_ARGS ] = { 2, "$+" },
- };
-
- size_t i, f;
-
- {
- size_t max = s.len;
- for (i = 0; i < s.len; ++i) {
- for (f = 0; f < ARRLEN(macro); ++f) {
- if (!strncmp(s.buf + i, macro[f].buf, macro[f].len)) {
- max += globals[f].len;
- }
- }
- }
- s.buf = realloc(s.buf, max + 27); /* I don't know, man */
- if (!s.buf) { return (string_t) { 0, NULL}; }
- memset(s.buf + s.len, 0, max - s.len);
- s.len = max;
- }
- for (i = 0; i < s.len; ++i) {
- for (f = 0; f < ARRLEN(macro); ++f) {
- if (!strncmp(s.buf + i, macro[f].buf, macro[f].len)) {
- insert(s.buf + i, s.len - i, globals[f].buf, globals[f].len, 2);
- }
- }
- }
- return s;
- }
-
- /* Strips all prefixing and leading whitespace.
- * Except if the last character beforehand is a newline. */
- static size_t
- strip(string_t s) {
- size_t i = s.len;
-
- if (!i)
- { return 0; }
-
- while (isspace(s.buf[i]))
- { --i; }
-
- s.buf[i] = '\0';
- for (i = 0; isspace(s.buf[i]); ++i);
-
- return i - (s.buf[i - 1] == '\n');
- }
-
- static int
- run(char * buf) {
- int ret = 127;
- fputs(GREEN "output" RESET ":\n", stderr);
- pid_t pid = fork();
- if (!pid) {
- execl("/bin/sh", "sh", "-c", buf, NULL);
- } else {
- int status;
- waitpid(pid, &status, 0);
- if (!WIFEXITED(status)) { ret = 126; }
- else { ret = WEXITSTATUS(status); }
- }
- return ret;
- }
-
- int
- main(int argc, char ** argv) {
- int ret = 0;
- string_t s = { 0, NULL };
-
- if (argc < 2
- || streq(argv[1], "-h")
- || streq(argv[1], "--help"))
- { goto help; }
-
- g_filename = (string_t) { strlen(argv[1]), argv[1] };
-
- if (streq(argv[1], "-n")
- || streq(argv[1], "--dry-run")) {
- if (argc > 2) {
- ret = 1;
- g_filename = (string_t) { strlen(argv[2]), argv[2] };
- }
- else { goto help; }
- }
-
- s = file_find_region(g_filename.buf, START, STOP);
-
- if (!s.buf) {
- if (errno)
- { fprintf(stderr, BOLD RED "%s" RESET ": %s\n", g_filename.buf, strerror(errno)); }
- else
- { fprintf(stderr, BOLD RED "%s" RESET ": File unrecognized.\n", g_filename.buf); }
- return 1;
- }
-
- g_all = all_args(argc, argv);
- g_short = shorten(g_filename);
- root(g_filename);
-
- s = expand(s);
- free(g_short.buf); free(g_all.buf);
- if (!s.buf) { return 1; }
-
- fprintf(stderr, GREEN "%s" RESET ": %s\n", argv[0], s.buf + strip(s));
- ret = ret ? 0 : run(s.buf);
- if (ret)
- { fprintf(stderr, RED "result" RESET ": " BOLD "%d, %s\n" RESET, errno, strerror(errno)); }
-
- free(s.buf);
- return ret;
- help:
- fprintf(stderr, YELLOW "%s" RESET ": %s", argv[0], HELP DESC);
- return 1;
- }
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