bake/bake.c

570 lines
12 KiB
C

/* 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 @FILENAME -o @{@SHORT} @ARGS @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 <limits.h>
#include "config.h"
#define START "@BAKE"
#define STOP "@STOP"
#define EXPUNGE_START "@{"
#define EXPUNGE_STOP "}"
#define VERSION "20240404"
#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 put first, may be merged together]\n" \
"\t" DIM "-v --version" RESET ", " DIM "-h --help" RESET ", " \
BOLD "-n --dry-run" RESET ", " BOLD "-x --expunge\n" RESET \
"Expansions\n" \
"\t" YELLOW "@FILENAME" RESET " returns target-file (abc.x.txt)\n" \
"\t" YELLOW "@SHORT " RESET " returns target-file without suffix (^-> abc.x)\n" \
"\t" YELLOW "@ARGS " RESET " returns " GREEN "arguments" RESET "\n" \
"Additional Features And Notes\n" \
"\t" YELLOW "@{" RESET BOLD "EXPUNGE_THIS_FILE" YELLOW "}" RESET \
" inline region to delete this or many files or directories,\n" \
"\tnon-recursive, only one file per block, removed from left to right. This has no\n" \
"\tinfluence on the normal command execution.\n" \
"\t" YELLOW "\\" RESET \
"SPECIAL_NAME will result in SPECIAL_NAME in the executed shell command.\n" \
"Backslashing is applicable to all meaningful symbols in Bake, it is ignored otherwise."
#define COPYRIGHT "2023 Emil Williams"
#define LICENSE "Licensed under the GNU Public License version 3 only, see LICENSE."
#define FILENAME_LIMIT (FILENAME_MAX)
#define BAKE_ERROR 127
enum {
BAKE_UNRECOGNIZED,
BAKE_MISSING_SUFFIX,
};
enum {
BAKE_RUN = 0,
BAKE_NORUN = (1 << 0),
BAKE_EXPUNGE = (1 << 1),
};
#define ARRLEN(a) (sizeof(a) / sizeof(a[0]))
#if INCLUDE_AUTONOMOUS_COMPILE
__attribute__((__section__(".text"))) static char autonomous_compile[] =
"@BAKE cc -std=c89 -O2 $@.c -o $@ $+ @STOP";
#endif
static int bake_errno;
typedef struct {
size_t len;
char * buf;
} string_t;
typedef string_t map_t;
/*** root ***/
static void
swap(char * a, char * b) {
*a ^= *b;
*b ^= *a;
*a ^= *b;
}
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;
}
/*** find region in file ***/
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;
}
static char *
find(char * buf, char * x, char * end) {
size_t xlen = strlen(x);
char * start = buf;
for (; buf <= end - xlen; ++buf) {
if (!strncmp(buf, x, xlen)) {
if (start < buf && buf[-1] == '\\') {
continue;
} else {
return buf;
}
}
}
return NULL;
}
static char *
get_region(string_t m, char * findstart, char * findstop) {
char * buf = NULL, * start, * stop, * end = m.len + m.buf;
start = find(m.buf, findstart, end);
if (start) {
start += strlen(findstart);
#ifdef REQUIRE_SPACE
if (!isspace(*start)) {
bake_errno = BAKE_MISSING_SUFFIX;
return NULL;
}
#endif /* REQUIRE_SPACE */
stop = find(start, findstop, end);
if (!stop) {
stop = start;
while (stop < end && *stop != '\n') {
if (stop[0] == '\\'
&& stop[1] == '\n') {
stop += 2;
}
++stop;
}
}
buf = strndup(start, (size_t)(stop - start));
}
return buf;
}
static char *
file_get_region(char * fn, char * start, char * stop) {
map_t m = map(fn);
char * buf = NULL;
if (m.buf) {
buf = get_region(m, start, stop);
munmap(m.buf, m.len);
}
return buf;
}
/*** g_short, g_all ***/
static char *
shorten(char * fn) {
size_t i, last, len;
static char sh[FILENAME_LIMIT];
len = strlen(fn);
for (last = 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 > 0) {
size_t i, len = argc;
for (i = 0; i < argc; ++i) {
len += strlen(argv[i]);
}
all = malloc(len + 1);
all[len] = '\0';
for (len = 0, i = 0; i < argc; ++i) {
strcpy(all + len, argv[i]);
len += strlen(argv[i]) + 1;
if (i + 1 < argc) {
all[len - 1] = ' ';
}
}
}
return all ? all : calloc(1, 1);
}
/*** insert, expand, bake_expand ***/
static void
insert(char * str, char * new, size_t slen, size_t nlen, size_t shift) {
memmove(str + nlen, str + shift, slen + 1 - shift);
memcpy(str, new, nlen);
}
static char *
expand(char * buf, char * macro, char * with) {
ssize_t i,
blen = strlen(buf),
mlen = strlen(macro),
wlen = strlen(with),
nlen;
fflush(stdout);
for (i = 0; i < blen - mlen + 1; ++i) {
if (!strncmp(buf + i, macro, mlen)) {
if (i && buf[i - 1] == '\\') {
memmove(buf + i - 1, buf + i, blen - i);
buf[blen - 1] = '\0';
} else {
nlen = wlen - mlen + 1;
if (nlen > 0) {
buf = realloc(buf, blen + nlen);
}
insert(buf + i, with, blen - i, wlen, mlen);
blen += (nlen > 0) * nlen;
}
}
}
return buf;
}
static char *
bake_expand(char * buf, char * filename, int argc, char ** argv) {
enum {
MACRO_FILENAME,
MACRO_SHORT,
MACRO_ARGS,
MACRO_STOP,
MACRO_NONE
};
char * macro[MACRO_NONE],
* macro_old[MACRO_STOP];
size_t i;
macro[MACRO_FILENAME] = "@FILENAME";
macro[MACRO_SHORT ] = "@SHORT";
macro[MACRO_ARGS ] = "@ARGS";
macro[MACRO_STOP ] = "@STOP";
macro_old[MACRO_FILENAME] = "$@";
macro_old[MACRO_SHORT ] = "$*";
macro_old[MACRO_ARGS ] = "$+";
char * global[4];
global[MACRO_FILENAME] = filename;
global[MACRO_SHORT ] = shorten(filename);
global[MACRO_ARGS ] = all_args((size_t) argc, argv);
global[MACRO_STOP ] = "";
#if NEW_MACROS
for (i = 0; i < ARRLEN(macro); ++i) {
buf = expand(buf, macro[i], global[i]);
}
#endif
#if OLD_MACROS
for (i = 0; i < ARRLEN(macro_old); ++i) {
buf = expand(buf, macro_old[i], global[i]);
}
#endif
free(global[MACRO_ARGS]);
return buf;
}
static void
remove_expand(char * buf, char * argv0, int rm, char * start, char * stop) {
size_t i, f, end = strlen(buf);
size_t startlen = strlen(start), stoplen = strlen(stop);
char x[1] = {'\0'};
for (i = 0; i < end; ++i) {
if (!strncmp(buf + i, start, startlen)) {
if (buf + i > buf && buf[i - 1] == '\\') {
continue;
}
for (f = i; f < end; ++f) {
if (!strncmp(buf + f, stop, stoplen)) {
if (buf + f > buf && buf[f - 1] == '\\') {
continue;
}
insert(buf + f, "", end - f, 0, 1);
i += startlen;
if (rm & BAKE_EXPUNGE) {
swap(buf + i + (f - i), x);
printf("%s: %sremoving '%s'\n",
argv0, rm & BAKE_NORUN ? "not " : "", buf + i);
if (!(rm & BAKE_NORUN)) {
remove(buf + i);
}
swap(buf + i + (f - i), x);
}
goto next;
}
}
goto stop;
}
next:
}
stop:
expand(buf, start, "");
}
/*** strip, run ***/
/* 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 (i && isspace(buf[i - 1])) {
--i;
}
buf[i] = '\0';
for (i = 0; isspace(buf[i]); ++i);
if (i && buf[i - 1] == '\n') {
--i;
}
return i;
}
static int
run(char * buf, char * argv0) {
puts(BOLD GREEN "output" RESET ":\n");
pid_t pid;
if ((pid = fork()) == 0) {
execl("/bin/sh", "sh", "-c", buf, NULL);
return 0; /* execl overwrites the process anyways */
} else if (pid == -1) {
fprintf(stderr, BOLD RED "%s" RESET ": %s, %s\n",
argv0, "Fork Error", strerror(errno));
return BAKE_ERROR;
} else {
int status;
if (waitpid(pid, &status, 0) < 0) {
fprintf(stderr, BOLD RED "%s" RESET ": %s, %s\n",
argv0, "Wait PID Error", strerror(errno));
return BAKE_ERROR;
}
if (!WIFEXITED(status)) {
return BAKE_ERROR;
}
return WEXITSTATUS(status);
}
}
/*** main ***/
int
main(int argc, char ** argv) {
int ret = BAKE_RUN;
char * buf = NULL,
* filename,
* argv0;
argv0 = argv[0];
if (argc < 2) {
goto help;
}
while (++argv, --argc && argv[0][0] == '-') {
++argv[0];
if (argv[0][1] == '-') {
++argv[0];
if (!strcmp(argv[0], "help")) {
goto help;
} else if (!strcmp(argv[0], "version")) {
goto version;
} else if (!strcmp(argv[0], "expunge")) {
ret |= BAKE_EXPUNGE;
} else if (!strcmp(argv[0], "dry-run")) {
ret |= BAKE_NORUN;
} else {
puts("UNKNOWN");
goto help;
}
} else do {
switch (argv[0][0]) {
case 'h':
goto help;
case 'v':
goto version;
case 'x':
ret |= BAKE_EXPUNGE;
break;
case 'n':
ret |= BAKE_NORUN;
break;
case 0 :
goto next;
default :
puts("UNKNOWN");
goto help;
}
} while (++(argv[0]));
next:
}
filename = argv[0];
++argv, --argc;
if (strlen(filename) > FILENAME_LIMIT) {
fprintf(stderr, BOLD RED "%s" RESET
": Filename too long (exceeds %d)\n",
argv0,
FILENAME_LIMIT);
return BAKE_ERROR;
}
root(&filename);
buf = file_get_region(filename, START, STOP);
if (!buf) {
char * error[2];
error[0] = "File Unrecognized";
error[1] = "Found start without suffix spacing";
fprintf(stderr, BOLD RED "%s" RESET ": '" BOLD "%s" RESET "' %s.\n",
argv0, filename, errno ? strerror(errno) : error[bake_errno]);
return BAKE_ERROR;
}
buf = bake_expand(buf, filename, argc, argv);
printf(BOLD GREEN "%s" RESET ": %s\n", argv0, buf + strip(buf));
remove_expand(buf, argv0, ret, EXPUNGE_START, EXPUNGE_STOP);
if (!ret) {
ret = run(buf, argv0);
if (ret) {
printf(BOLD RED "result" RESET ": " BOLD "%d\n" RESET, ret);
}
} else { ret = 0; }
free(buf);
return ret;
help:
fprintf(stderr, YELLOW "%s" RESET ": %s\n", argv0, HELP DESC);
return BAKE_ERROR;
version:
fprintf(stderr,
YELLOW "%s" RESET ": v" VERSION "\n"
"Copyright " COPYRIGHT "\n" LICENSE "\n",
argv0);
return BAKE_ERROR;
}