libc: option parsing (hasflag/optval); wc -l/-w/-c, head -n N

- hasflag(argv,argc,f): single-char flag present (-f or within -abc)
- optval(argv,argc,opt): value for -opt (-n 5 or -n5)
- wc supports -l/-w/-c (default all); head supports -n N (and bare N)

1 files changed, 14 insertions, 9 deletions

diff --git a/c/wc.c b/c/wc.c
index a957542..86c3aed 100644
--- a/c/wc.c
+++ b/c/wc.c
@@ -1,20 +1,25 @@
 #include "gbos.h"
-/* wc: count lines, words, chars of stdin (like `wc`). */
+/* wc [-l] [-w] [-c]: count lines, words, chars of stdin (default: all). */
 void main(void) {
+    char *argv[8];
+    unsigned char argc = argv_parse(argv, 8);
+    unsigned char wl = hasflag(argv, argc, 'l');
+    unsigned char ww = hasflag(argv, argc, 'w');
+    unsigned char wch = hasflag(argv, argc, 'c');
     unsigned int lines = 0, words = 0, chars = 0;
-    unsigned char inword = 0;
+    unsigned char inword = 0, first = 1;
     char c;
+    if (!wl && !ww && !wch) { wl = ww = wch = 1; }
     for (;;) {
         c = readc();
         if (c == EOF) break;
         chars++;
         if (c == '\n') lines++;
-        if (c == ' ' || c == '\n' || c == '\r' || c == '\t') {
-            inword = 0;
-        } else if (!inword) {
-            inword = 1;
-            words++;
-        }
+        if (c == ' ' || c == '\n' || c == '\r' || c == '\t') inword = 0;
+        else if (!inword) { inword = 1; words++; }
     }
-    putu(lines); putc(' '); putu(words); putc(' '); putu(chars); nl();
+    if (wl)  { putu(lines); first = 0; }
+    if (ww)  { if (!first) putc(' '); putu(words); first = 0; }
+    if (wch) { if (!first) putc(' '); putu(chars); }
+    nl();
 }