/* bake.c - Ever burned a cake? * Copyright 2023 Emil Williams * * Licensed under the GNU Public License version 3 only, see LICENSE. * * @BAKE cc -std=c89 -O2 -I. $@ -o $* $+ # @STOP */ #define _POSIX_C_SOURCE 200809L #include #include #include #include #include #include #include #include #include #include #include #include #include #include "config.h" #define START "@BAKE" #define STOP "@STOP" #define HELP \ BOLD "[option] target-file" RESET " [" GREEN "arguments" RESET " ...]\n" \ "Use the format `" BOLD "@BAKE" RESET " cmd ...' within the target-file, this will execute the\n" \ "rest of line, or if found within the file, until the " BOLD "@STOP" RESET " marker.\n" \ #define DESC \ "Options [Must always be first]\n" \ "\t" DIM "-h --help" RESET", " BOLD "-n --dry-run\n" RESET \ "Expansions\n" \ "\t" YELLOW "$@" 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" /*** Utility functions ***/ static void swap(char * a, char * b) { *a ^= *b; *b ^= *a; *a ^= *b; } static char * find(char * x, char * buf, char * end) { size_t len = strlen(x); for (; (buf < end) && len < (size_t)(end - buf); ++buf) { if (!strncmp(buf, x, len)) { return buf; } } return NULL; } static char * insert(char * new, char * str, size_t offset, size_t shift) { size_t len, max; len = strlen(new); max = (strlen(str) + 1 - offset - shift); memmove(str + offset + len, str + offset + shift, max); memcpy(str + offset, new, len); return str; } /*** g_short, g_all Functions ***/ static char * g_filename, * g_short, * g_all; static char * shorten(char * fn) { size_t i, last = 0, len; char * sh; len = strlen(fn); sh = malloc(len + 1); if (!sh) { return NULL; } for (i = 0; i < len; ++i) { if (fn[i] == '.') { last = i; } } last = last ? last : i; strncpy(sh, fn, last); sh[last] = '\0'; return sh; } static char * all_args(size_t argc, char ** argv) { char * all = NULL; if (argc > 2) { size_t i, len = argc; for (i = 2; i < argc; ++i) { len += strlen(argv[i]); } all = malloc(len + 1); if (!all) { return NULL; } all[len] = '\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 all; } /*** Map ***/ typedef struct { char * str; size_t len; } map_t; 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.str = (char *) mmap(NULL, m.len, PROT_READ, MAP_SHARED, fd, 0); } close(fd); } return m; } /*** Important Functions ***/ static char * find_region(map_t m) { extern char * strndup(const char * s, size_t n); /* for splint */ char * buf = NULL, * start, * stop; start = find(START, m.str, m.str + m.len); if (start) { start += strlen(START); #ifdef REQUIRE_SPACE if (!isspace(*start)) { fprintf(stderr, RED "%s" RESET ": Found start without suffix spacing.\n", g_filename); return buf; } #endif /* REQUIRE_SPACE */ stop = find(STOP, start, start + m.len - (start - m.str)); if (!stop) { stop = start; while (*stop && *stop != '\n') { if (stop[0] == '\\' && stop[1] == '\n') { stop += 2; } ++stop; } } if (stop) { buf = strndup(start, (size_t) (stop - m.str) - (start - m.str)); } } return buf; } static int root(char ** rootp) { char x[1] = {'\0'}; char * root = *rootp; size_t len = strlen(root); 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; } static size_t expand_size(char * buf, int argc, char ** argv) { size_t i, len, max; len = max = strlen(buf) + 1; for (i = 0; i < len; ++i) { if (buf[i] == '\\') { i += 2; continue; } else if (buf[i] == '$') { switch (buf[++i]) { case '@': max += strlen(g_filename); break; case '*': if (!g_short) { g_short = shorten(g_filename); } max += g_short ? strlen(g_short) : 0; break; case '+': if (!g_all) { g_all = all_args((size_t) argc, argv); } max += g_all ? strlen(g_all) : 0; break; } } } return max; } static char * expand(char * buf) { size_t i; char * ptr = NULL; for (i = 0; buf[i]; ++i) { if (buf[i] == '\\') { i += 2; continue; } else if (buf[i] == '$') { switch (buf[++i]) { case '@': ptr = g_filename; break; case '*': ptr = g_short; break; case '+': ptr = g_all ? g_all : ""; break; default: continue; } buf = insert(ptr, buf, i - 1, 2); } } free(g_short); free(g_all); return buf; } /* Strips all prefixing and leading whitespace. * Except if the last character beforehand is a newline. */ static size_t strip(char * buf) { size_t i = strlen(buf); if (!i) { return 0; } while (isspace(buf[i - 1])) { --i; } buf[i] = '\0'; for (i = 0; isspace(buf[i]); ++i); return i - (buf[i - 1] == '\n'); } static int run(char * buf) { fputs(GREEN "output" RESET ":\n", stderr); return system(buf); } int main(int argc, char ** argv) { int ret = 0; char * buf = NULL; if (argc < 2 || !strcmp(argv[1], "-h") || !strcmp(argv[1], "--help")) { goto help; } g_filename = argv[1]; if (!strcmp(argv[1], "-n") || !strcmp(argv[1], "--dry-run")) { if (argc > 2) { ret = 1; g_filename = argv[2]; } else { goto help; } } { map_t m = map(g_filename); if (m.str) { buf = find_region(m); munmap(m.str, m.len); } } if (!buf) { if (errno) { fprintf(stderr, BOLD RED "%s" RESET ": %s\n", g_filename, strerror(errno)); } else { fprintf(stderr, BOLD RED "%s" RESET ": File unrecognized.\n", g_filename); } return 1; } root(&g_filename); { char * buf2 = buf; buf = realloc(buf, expand_size(buf, argc, argv)); if (!buf) { free(buf2); free(g_short); free(g_all); return 1; } } buf = expand(buf); fprintf(stderr, GREEN "%s" RESET ": %s\n", argv[0], buf + strip(buf)); ret = ret ? 0 : run(buf); if (ret) { fprintf(stderr, RED "result" RESET ": " BOLD "%d\n" RESET, ret); } free(buf); return ret; help: fprintf(stderr, YELLOW "%s" RESET ": %s", argv[0], HELP DESC); return 1; }