add mseq (replaces next)

1 files changed, 172 insertions, 0 deletions

diff --git a/mseq.c b/mseq.c
new file mode 100644
index 0000000..7c65c8e
--- /dev/null
+++ b/mseq.c
@@ -0,0 +1,172 @@
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <limits.h>
+#include <errno.h>
+
+char *
+seq_open(char *file)
+{
+	int fd;
+	struct stat st;
+
+	// env $SEQ or something
+	if (!file)
+		file = "map";
+	fd = open(file, O_RDONLY);
+	if (!fd)
+		return 0;
+
+	fstat(fd, &st);
+	char *map = mmap(0, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+	close(fd);
+
+	if (map == MAP_FAILED)
+		return 0;
+
+	return map;
+}
+
+static const char *
+readlin(const char *p)
+{
+        static char b[PATH_MAX];
+        int r = readlink(p, b, sizeof b - 1);
+        if (r < 0)
+		r = 0;
+        b[r] = 0;
+        return b;
+}
+
+char *
+parse_relnum(char *a, long cur, long last, long *out)
+{
+	long base;
+	char *b;
+
+	if (strcmp(a, "+") == 0)
+		a = ".+1";
+	else if (strcmp(a, "-") == 0)
+		a = ".-1";
+	else if (strcmp(a, "$") == 0)
+		a = "-1";
+	
+	if (*a == '.') {
+		a++;
+		base = cur;
+	} else if (*a == '-') {
+		base = last + 1;
+	} else {
+		base = 0;
+	}
+	errno = 0;
+	long d = strtol(a, &b, 10);
+	if (errno != 0) {
+		perror("strtol");
+		exit(1);
+	}
+
+	*out = base + d;
+	if (*out <= 0)
+		*out = 1;
+	if (*out > last)
+		*out = last;
+	
+	return b;
+}
+
+int
+main(int argc, char *argv[])
+{
+	char *map = seq_open(0);
+	if (!map)
+		return 1;
+
+	long lines;
+	long cur = 0;
+
+	const char *curfile = readlin("map.cur");
+	char *curpath;
+
+	char *s, *t;
+	for (s = map, lines = 0; s; s = t) {
+		t = strchr(s+1, '\n');
+		if (!t)
+			break;
+		s++;
+//		printf("{%.*s}\n", t-s, s);
+		lines++;
+		// XXX compare modulo whitespace
+		if (!cur &&
+		    strncmp(s, curfile, strlen(curfile)) == 0 &&
+		    s[strlen(curfile)] == '\n')
+			cur = lines;
+	}
+	lines--;
+
+	long i, start, stop;
+	for (i = 1; i < argc; i++) {
+		char *a = argv[i];
+		start = stop = 0;
+
+		while (*a && *a != ':') {
+			char *b = parse_relnum(a, cur, lines, &start);
+			if (a == b) {
+				printf("huh\n");
+				exit(1);
+			}
+			a = b;
+		}
+		if (*a == ':') {
+			a++;
+			if (!*a) {
+				stop = lines;
+			} else {
+				char *b = parse_relnum(a, cur, lines, &stop);
+				if (a == b) {
+					printf("huh\n");
+					exit(1);
+				}
+				a = b;
+			}
+		} else if (!*a) {
+			stop = start;
+		} else {
+			printf("huh\n");
+			exit(1);
+		}
+
+		long line;
+		for (s = map, line = 0; s; s = t) {
+			t = strchr(s+1, '\n');
+			if (!t)
+				break;
+			s++;
+			line++;
+
+			if (line >= start && line <= stop) {
+				fwrite(s, 1, t-s, stdout);
+				putchar('\n');
+				cur = line;
+				curpath = s;
+				while (*curpath == ' ')
+					curpath++;
+			}
+		}
+	}
+
+/*
+	char *e = strchr(curpath, '\n');
+	unlink("map.cur-");
+	symlink(strndup(curpath, e-curpath), "map.cur-");
+	rename("map.cur-", "map.cur");
+*/
+
+	return 0;
+}