[hackers] [PATCH 1/6] ed: Add optional parameter to string()

[Roberto E. Vargas Caballero]

This makes possible to use the function to initialize the string from
an existing char array.
---
 ed.c | 30 +++++++++++++++++++++---------
 1 file changed, 21 insertions(+), 9 deletions(-)

diff --git a/ed.c b/ed.c
index b430e74..13e956a 100644
--- a/ed.c
+++ b/ed.c
@@ -122,12 +122,24 @@ prevln(int line)
 }
 
 static String *
-string(String *s)
+string(String *s, char *from)
 {
+       size_t len;
+       char *t;
+
+       if (!from) {
+               len = 0;
+               t = NULL;
+       } else {
+               if ((t = strdup(from)) == NULL)
+                       error("out of memory");
+               len = strlen(t);
+       }
+
        free(s->str);
-       s->str = NULL;
-       s->siz = 0;
-       s->cap = 0;
+       s->str = t;
+       s->siz = len;
+       s->cap = len;
 
        return s;
 }
@@ -949,7 +961,7 @@ join(void)
        char *t, c;
        static String s;
 
-       string(&s);
+       string(&s, NULL);
        for (i = line1;; i = nextln(i)) {
                chksignals();
                for (t = gettxt(i); (c = *t) != '\n'; ++t)
@@ -1014,7 +1026,7 @@ execsh(void)
        skipblank();
        if ((c = input()) != '!') {
                back(c);
-               string(&cmd);
+               string(&cmd, NULL);
        } else if (cmd.siz) {
                --cmd.siz;
                repl = 1;
@@ -1048,7 +1060,7 @@ getrhs(int delim)
        int c;
        static String s;
 
-       string(&s);
+       string(&s, NULL);
        while ((c = input()) != '\n' && c != EOF && c != delim)
                addchar(c, &s);
        addchar('\0', &s);
@@ -1152,7 +1164,7 @@ subline(int num, int nth)
        int i, m, changed;
        static String s;
 
-       string(&s);
+       string(&s, NULL);
        i = changed = 0;
        for (m = match(num); m; m = rematch(num)) {
                chksignals();
@@ -1456,7 +1468,7 @@ doglobal(void)
        int cnt, ln, k;
 
        skipblank();
-       string(&cmdline);
+       string(&cmdline, NULL);
        gflag = 1;
        if (uflag)
                chkprint(0);
-- 
2.37.3