add pager

2 files changed, 59 insertions, 0 deletions

diff --git a/lib/cstr/cstr.c b/lib/cstr/cstr.c
index f464cf3..9f4ad6f 100644
--- a/lib/cstr/cstr.c
+++ b/lib/cstr/cstr.c
@@ -175,6 +175,50 @@ u64 strip_cstr(char *cstr, char strip)
 	return strip_front(cstr, strip) + strip_back(cstr, strip);
 }
 
+
+u64 number_of_lines(const char *cstr)
+{
+	u64 lines = 0;
+
+	while (*cstr) {
+		if (*cstr == '\n') ++lines;
+		++cstr;
+	}
+
+	return lines;
+}
+
+
+substr_t getline(const char *cstr, u64 n)
+{
+	substr_t line;
+	line.begin = (char *)cstr;
+	line.end = line.begin;
+
+	while (*line.end && *line.end != '\n') ++line.end;
+
+	for (int i = 0; i < n; ++i)
+		line = nextline(line);
+
+	return line;
+}
+
+
+substr_t nextline(substr_t line)
+{
+	if (!(*line.end || *(line.end + 1))) {
+		line.begin = 0;
+		line.end = 0;
+		return line;
+	}
+
+	line.begin = ++line.end;
+
+	while (*line.end && *line.end != '\n') ++line.end;
+
+	return line;
+}
+
 /* DOC
  * @type function
  * @name string_utf8_length
@@ -272,6 +316,12 @@ void u64_to_cstr(u64 n, char *cstr, u64 length)
 		n /= 10;
 	}
 
+	if (p == cstr + length - 1) {
+		*(p--) = '0';
+	}
+
+	*p = 0;
+
 	d = p - cstr + 1;
 
 	for (i = 0; i < length - d; ++i)
diff --git a/lib/cstr/cstr.h b/lib/cstr/cstr.h
index 80dc359..ce27eb0 100644
--- a/lib/cstr/cstr.h
+++ b/lib/cstr/cstr.h
@@ -3,6 +3,11 @@
 
 #include "../sys/sizes.h"
 
+typedef struct {
+	char *begin;
+	char *end;
+} substr_t;
+
 u64        cstr_length(const char *);
 i8         cstr_compare(const char *a, const char *b);
 u64        cstr_split(char *cstr, char split);
@@ -10,6 +15,10 @@ const char *next_split(const char *previous);
 u64        strip_front(char *cstr, char strip);
 u64        strip_back(char *cstr, char strip);
 u64        strip_cstr(char *cstr, char strip);
+u64        number_of_lines(const char *cstr);
+
+substr_t   getline(const char *cstr, u64 n);
+substr_t   nextline(substr_t line);
 
 u64 cstr_utf8_length(const char *);
 u8  next_utf8(const char **);