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-rw-r--r--gpp.c245
1 files changed, 245 insertions, 0 deletions
diff --git a/gpp.c b/gpp.c
new file mode 100644
index 0000000..569ae76
--- /dev/null
+++ b/gpp.c
@@ -0,0 +1,245 @@
+/* See LICENSE file for copyright and license details. */
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "arg.h"
+
+
+char *argv0;
+
+
+static void
+usage(void)
+{
+ fprintf(stderr, "usage: %s [-D name[=value]] [-f file | [-i input-file] [-o output-file]] "
+ "[-n count] [-s symbol] [-u [-u]] [shell [argument] ...]\n", argv0);
+ exit(1);
+}
+
+
+static int
+get_fd(const char *path)
+{
+ const char *p;
+ char *s;
+ long int tmp;
+
+ if (!strcmp(path, "/dev/stdin"))
+ return STDIN_FILENO;
+ if (!strcmp(path, "/dev/stdout"))
+ return STDOUT_FILENO;
+ if (!strcmp(path, "/dev/stderr"))
+ return STDERR_FILENO;
+
+ if (!strncmp(path, "/dev/fd/", sizeof("/dev/fd/") - 1))
+ p = &path[sizeof("/dev/fd/") - 1];
+ else if (!strncmp(path, "/proc/self/fd/", sizeof("/proc/self/fd/") - 1))
+ p = &path[sizeof("/proc/self/fd/") - 1];
+ else
+ return -1;
+
+ if (!isdigit(*p))
+ return -1;
+ errno = 0;
+ tmp = strtol(p, &s, 10);
+ if (errno || tmp > INT_MAX || *s)
+ return -1;
+ return (int)tmp;
+}
+
+
+static int
+xopen(const char *path, int *do_close)
+{
+ int fd = get_fd(path);
+ if (fd >= 0) {
+ *do_close = 0;
+ return fd;
+ }
+ fd = open(path, O_RDONLY);
+ if (fd < 0) {
+ fprintf(stderr, "%s: open %s O_RDONLY: %s\n", argv0, path, strerror(errno));
+ exit(1);
+ }
+ *do_close = 1;
+ return fd;
+}
+
+
+static int
+xcreate(const char *path)
+{
+ int fd = get_fd(path);
+ if (fd >= 0)
+ return fd;
+ fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0666);
+ if (fd < 0) {
+ fprintf(stderr, "%s: open %s O_WRONLY|O_CREAT|O_TRUNC 0666: %s\n", argv0, path, strerror(errno));
+ exit(1);
+ }
+ return fd;
+}
+
+
+int
+main(int argc, char *argv[])
+{
+ const char *shell_[] = {"bash", NULL}, **shell = shell_;
+ const char *input_file = NULL;
+ const char *output_file = NULL;
+ const char *symbol = NULL;
+ int iterations = -1;
+ int unshebang = 0;
+ long int tmp;
+ char *arg, *p, *q;
+ char *in_data = NULL, *out_data = NULL;
+ size_t in_size = 0, in_len = 0, in_off = 0;
+ size_t out_size = 0, out_len = 0, out_off = 0;
+ int in_fd, out_fd, do_close;
+ ssize_t r;
+
+ ARGBEGIN {
+ case 'D':
+ arg = EARGF(usage());
+ if (!*arg || *arg == '=')
+ usage();
+ p = strchr(arg, '=');
+ if (p)
+ *p++ = '\0';
+ if (setenv(arg, p ? p : "1", 1)) {
+ fprintf(stderr, "%s: setenv %s %s 1: %s\n", argv0, arg, p ? p : "1", strerror(errno));
+ return 1;
+ }
+ break;
+ case 'f':
+ if (input_file || output_file)
+ usage();
+ input_file = output_file = EARGF(usage());
+ if (!*input_file)
+ usage();
+ break;
+ case 'i':
+ if (input_file)
+ usage();
+ input_file = EARGF(usage());
+ if (!*input_file)
+ usage();
+ break;
+ case 'n':
+ if (iterations >= 0)
+ usage();
+ arg = EARGF(usage());
+ if (!isdigit(*arg))
+ usage();
+ errno = 0;
+ tmp = strtol(arg, &arg, 10);
+ if (errno || tmp > INT_MAX || *arg)
+ usage();
+ iterations = (int)tmp;
+ break;
+ case 'o':
+ if (output_file)
+ usage();
+ output_file = EARGF(usage());
+ if (!*output_file)
+ usage();
+ break;
+ case 's':
+ if (symbol)
+ usage();
+ symbol = EARGF(usage());
+ break;
+ case 'u':
+ if (unshebang == 2)
+ usage();
+ unshebang += 1;
+ break;
+ default:
+ usage();
+ } ARGEND;
+
+ if (argc)
+ shell = (void *)argv;
+
+ if (setenv("_GPP", argv0, 1))
+ fprintf(stderr, "%s: setenv _GPP %s 1: %s\n", argv0, argv0, strerror(errno));
+
+ if (iterations < 0)
+ iterations = 1;
+ if (!symbol)
+ symbol = "@";
+ if (!input_file || (input_file[0] == '-' && !input_file[1]))
+ input_file = "/dev/stdin";
+ if (!output_file || (output_file[0] == '-' && !output_file[1]))
+ output_file = "/dev/stdout";
+
+ in_fd = xopen(input_file, &do_close);
+ for (;;) {
+ if (in_len == in_size) {
+ in_data = realloc(in_data, in_size += 8096);
+ if (!in_data) {
+ fprintf(stderr, "%s: realloc: %s\n", argv0, strerror(errno));
+ return 1;
+ }
+ }
+ r = read(in_fd, &in_data[in_len], in_size - in_len);
+ if (r <= 0) {
+ if (!r)
+ break;
+ fprintf(stderr, "%s: read %s: %s\n", argv0, input_file, strerror(errno));
+ }
+ in_len += (size_t)r;
+ }
+ if (do_close)
+ close(in_fd);
+
+ if (unshebang && in_len >= 2 && in_data[0] == '#' && in_data[1] == '!') {
+ p = memchr(in_data, '\n', in_len);
+ if (!p)
+ goto after_unshebang;
+ in_off = (size_t)(++p - in_data);
+ if (in_off == in_len)
+ goto after_unshebang;
+ if (unshebang >= 2) {
+ q = memchr(p--, '\n', in_len - in_off);
+ if (!q)
+ goto after_unshebang;
+ memmove(p, &p[1], (size_t)(q - in_data) - in_off--);
+ *--q = '\n';
+ }
+ }
+after_unshebang:
+
+ while (iterations--) {
+ /* TODO parse: in -> out */
+
+ in_len = 0;
+ in_off = 0;
+
+ /* TODO shell: out -> in */
+
+ out_len = 0;
+ out_off = 0;
+ }
+
+ free(out_data);
+ out_fd = xcreate(output_file);
+ while (in_off < in_len) {
+ r = write(out_fd, &in_data[in_off], in_len - in_off);
+ if (r <= 0) {
+ fprintf(stderr, "%s: write %s: %s\n", argv0, output_file, strerror(errno));
+ return 1;
+ }
+ in_off += (size_t)r;
+ }
+ if (close(out_fd))
+ fprintf(stderr, "%s: write %s: %s\n", argv0, output_file, strerror(errno));
+ free(in_data);
+ return 0;
+}