svex

commit 80df69e9275a217c6902d4f89a28ee773510b2e0
parent 485d36fbf2b426f1e6a909e8b7aedf6b8bed2568
Author: zavok <an2qzavok@gmail.com>
Date:   Sun, 23 Aug 2020 20:49:24 +0300

merge

Diffstat:
M
Makefile
 | 
4
+++-
M
svex.c
 | 
117
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--

2 files changed, 118 insertions(+), 3 deletions(-)
diff --git a/Makefile b/Makefile
@@ -7,6 +7,8 @@ BIN = svex
 MAN = $(BIN).1
 OBJ = $(BIN:=.o)
 
+CPPFLAGS = '-D_POSIX_C_SOURCE=200809L'
+
 all: $(BIN)
 
 $(BIN): $(OBJ)
@@ -29,4 +31,4 @@ clean:
 	rm -f $(BIN) $(OBJ)
 
 .c.o:
-	$(CC) $(CFLAGS) -c $<
+	$(CC) $(CPPFLAGS) $(CFLAGS) -c $<
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 +14,14 @@ char *argv0;
 char *fname;
 
 char *buff;
-ulong blen;
+long blen;
+long curp, addr[2];
 
 void load(void);
+int parseaddr(char*, long*);
+char* getrow(long);
+int printrow(long);
+void edit();
 
 void
 usage (void)
@@ -25,8 +33,8 @@ usage (void)
 int
 main (int argc, char *argv[])
 {
-	blen = 0;
 	buff = 0;
+	blen = 0;
 	ARGBEGIN{
 	default: usage();
 	} ARGEND
@@ -35,16 +43,78 @@ main (int argc, char *argv[])
 		fname = argv[0];
 		load();
 	}
+	curp = 1;
+	for (;;){
+		long n;
+		char ibuf[1024];
+		char *cmd;
+		n = read(0, ibuf, 1024);
+		ibuf[n] = 0;
+		cmd = ibuf + parseaddr(ibuf, addr);
+		switch (cmd[0]){
+		case 'p':
+			printrow(addr[0]);
+			break;
+		case '\0':
+		case 'q':
+			exit(0);
+			break;
+		default :
+			printf("?\n");
+		}
+		curp = addr[1];
+	}
 	return 0;
 }
 
 void
+edit(void)
+{
+	for (;;) {
+		
+	}
+}
+
+int
+parseaddr(char *buf, long *addr)
+{
+	long n;
+	char *bp;
+	*addr = curp; 
+	bp = buf;
+	switch (buf[0]){
+	case '.':
+		// current position
+		*addr = curp;
+		bp++;
+		break;
+	case '$':
+		// last line
+		break;
+	case '/':
+		// regex search forward
+		break;
+	case '?':
+		// regex search backward
+		break;
+	default:
+		n = strtol(buf, &bp, 10);
+		if (bp != buf) *addr = n;
+	}
+	return (bp - buf);
+}
+
+void
 load(void)
 {
 	int f;
 	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(buff+blen, b, n);
@@ -52,3 +122,46 @@ load(void)
 	}
 	close(f);
 }
+
+char*
+getrow(long rn)
+{
+	char *p;
+	long n;
+	n = 1;
+	p = buff;
+	if (blen == 0) return 0;
+	while (n < rn) {
+		if (*p == '\n') n++;
+		p++;
+		if (p > buff + blen) return 0;
+	}
+	return p;
+}
+
+int
+printrow(long rn)
+{
+	char *p;
+	int col;
+	col = 0;
+	p = getrow(rn);	
+	if (p == 0) return 0;
+	printf("----[ %ld ]---------\n", rn);
+	for (;;) {
+		switch (*p){
+		case '\t':
+			write(1, "\n", 1);
+			col++;
+			break;
+		case '\n':
+			write(1, "\n\n", 2);
+			return 0;
+		default:
+			write(1, p, 1);
+		}
+		p++;
+		if (p > buff+blen) return -1;
+	}
+	return 0;
+}