ed

commit f2593570542c7916d04f30e54f685eeb92cf5b90
parent 91e4a06811bd9d9358b2154bbf060de5250dd5db
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Sat, 12 Dec 2015 11:33:55 +0100

Add basic skeleton for s command

This code only parses the input and set the variables
that are needed in the next step, go through the lines
addressed and apply the substituion.

Diffstat:
M
ed.c
 | 
85
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 85 insertions(+), 0 deletions(-)
diff --git a/ed.c b/ed.c
@@ -48,6 +48,9 @@ char *ocmdline;
 size_t cmdsiz, cmdcap;
 int repidx;
 
+int gsub;
+char *lhs, *rhs;
+
 static void
 error(char *msg)
 {
@@ -801,6 +804,83 @@ execsh(void)
 }
 
 static void
+getlhs(int delim)
+{
+	int c;
+	char *s;
+
+	back(c = input());
+	if (c == delim) {
+		if ((s = lastre) == NULL)
+			error("No previous substitution");
+	} else {
+		s = getregex(delim);
+	}
+	free(lhs);
+	if ((lhs = strdup(s)) == NULL)
+		error("out of memory");
+
+	compile(lhs);
+	if (input() != delim)
+		error("invalid pattern delimiter");
+}
+
+static void
+getrhs(int delim)
+{
+	char *repl;
+	int c;
+	size_t n, siz, cap;
+
+	repl = NULL;
+	siz = cap = 0;
+	while ((c = input()) != '\n' && c != EOF && c != delim) {
+		if (c == '\\') {
+			if (isdigit(c = input()))
+				back(c);
+		}
+		repl = addchar(c, repl, &siz, &cap);
+	}
+	back(c);
+	repl = addchar('\0', repl, &siz, &cap);
+
+	if (!strcmp("%", repl)) {
+		free(repl);
+		if (!rhs)
+			error("no previous substitution");
+	} else {
+		free(rhs);
+		rhs = repl;
+	}
+}
+
+static void
+subs(void)
+{
+	int c, delim;
+
+
+	if ((delim = input()) == '\n') {
+		if (!rhs || !lhs)
+			error("no previous substitution");
+	} else {
+		gsub = 0;
+		getlhs(delim);
+		getrhs(delim);
+
+		if (c == delim) {
+			if ((c = input()) == 'g')
+				gsub = 1;
+			else
+				back(c);
+		} else {
+			pflag = 'p';
+			back(c);
+		}
+	}
+}
+
+static void
 docmd(void)
 {
 	char *s, cmd;
@@ -879,6 +959,11 @@ repeat:
 		deflines(lastln, lastln);
 		printf("%d\n", line1);
 		break;
+	case 's':
+		deflines(curln, curln);
+		subs();
+		chkprint(1);
+		break;
 	case 'i':
 		if (nlines > 1)
 			goto bad_address;