svex

commit fd22de38ff77200ac4c4da8b23c6cdec1a3076ae
parent a41bc0926d3d369009bf864cffafe83313b73c30
Author: zavok <an2qzavok@gmail.com>
Date:   Sun,  1 Mar 2020 22:54:39 +0300

printrow and getrow funcs

Diffstat:
M
svex.c
 | 
73
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------

1 file changed, 66 insertions(+), 7 deletions(-)
diff --git a/svex.c b/svex.c
@@ -1,3 +1,6 @@
+/* following line is required to make dprintf work */
+#define _POSIX_C_SOURCE 200809L
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
@@ -11,9 +14,11 @@ char *argv0;
 char *fname;
 
 char *buff;
-ulong blen;
+long blen;
 
 void load(void);
+char* getrow(long);
+int printrow(long);
 
 void
 usage (void)
@@ -25,6 +30,8 @@ usage (void)
 int
 main (int argc, char *argv[])
 {
+	char *ip, ibuf[1024];
+	long n;
 	blen = 0;
 	buff = 0;
 	ARGBEGIN{
@@ -32,8 +39,20 @@ main (int argc, char *argv[])
 	} ARGEND
 	if (argc == 0) usage();
 	if (argc > 1) usage();
-	fname = argv[1];
+	fname = argv[0];
 	load();
+	for (;;){
+		n = read(0, ibuf, 1024);
+		ip = ibuf;
+		ibuf[n] = 0;
+		switch (ip[0]){
+		case 'q':
+			exit(0);
+			break;
+		default :
+			printf("?\n");
+		}
+	}
 	return 0;
 }
 
@@ -41,15 +60,55 @@ void
 load(void)
 {
 	int f;
-	ulong n;
-	char b[1024], *bp;
-	bp = buff;
+	long n;
+	char b[1024];
 	f = open(fname, O_RDONLY);
+	if (f == -1) {
+		dprintf(2, "failed to open file %s!\n", fname);
+		exit(-1);
+	}
 	while ((n = read(f, b, 1024)) > 0){
 		buff = realloc(buff, blen + n);
-		memcpy(bp, b, n);
-		bp += n;
+		memcpy(buff+blen, b, n);
 		blen += n;
 	}
 	close(f);
 }
+
+char*
+getrow(long rn)
+{
+	char *p;
+	long n;
+	n = 0;
+	p = buff;
+	while (n < rn) {
+		if (*p == '\n') n++;
+		p++;
+		if (p > buff + blen) return 0;
+	}
+	return p;
+}
+
+int
+printrow(long rn)
+{
+	char *p;
+	p = getrow(rn);	
+	printf("---[ %d ]----------\n", rn);
+	for (;;) {
+		switch (*p){
+		case '\t':
+			write(1, "\n", 1);
+			break;
+		case '\n':
+			write(1, "\n\n", 2);
+			return 0;
+		default:
+			write(1, p, 1);
+		}
+		p++;
+		if (p > buff+blen) return -1;
+	}
+	return 0;
+}