1 files changed, 67 insertions, 0 deletions
diff --git a/usr/libc.c b/usr/libc.c
new file mode 100644
index 0000000..a48a64c
--- /dev/null
+++ b/usr/libc.c
@@ -0,0 +1,67 @@
+/* gbos libc C helpers (compiled once, linked into every program). */
+#include "gbos.h"
+
+/* sleep for approximately 'ms' milliseconds (cooperative; other procs run).
+   The kernel counts in 1/64-second units (~15.6 ms), so we round ms to that. */
+void msleep(unsigned int ms) {
+    unsigned int u = ms >> 4;          /* ~ms/15.6, close enough for a delay */
+    if (u > 255) u = 255;
+    if (u == 0 && ms) u = 1;
+    gsleep((unsigned char)u);
+}
+
+/* print an unsigned int in decimal */
+void putu(unsigned int n) {
+    char buf[5];
+    unsigned char i = 0;
+    if (n == 0) { putc('0'); return; }
+    while (n) { buf[i++] = '0' + (n % 10); n = n / 10; }
+    while (i) putc(buf[--i]);
+}
+
+/* parse a decimal number (stops at the first non-digit) */
+unsigned char atou(const char *s) {
+    unsigned char n = 0;
+    while (*s >= '0' && *s <= '9') { n = n * 10 + (*s - '0'); s++; }
+    return n;
+}
+
+/* tokenize the argument string in place into argv[]; returns argc.
+   (replaces the spaces in the arg string with NULs) */
+unsigned char argv_parse(char **argv, unsigned char maxv) {
+    char *p = getargs();
+    unsigned char argc = 0;
+    for (;;) {
+        while (*p == ' ') p++;
+        if (*p == 0) break;
+        if (argc < maxv) argv[argc] = p;
+        argc++;
+        while (*p != 0 && *p != ' ') p++;
+        if (*p == ' ') *p++ = 0;
+    }
+    return argc;
+}
+
+/* return nonzero if single-char flag `f` appears (as -f or within -abc) */
+unsigned char hasflag(char **argv, unsigned char argc, char f) {
+    unsigned char i, j;
+    for (i = 0; i < argc; i++) {
+        if (argv[i][0] != '-') continue;
+        for (j = 1; argv[i][j]; j++)
+            if (argv[i][j] == f) return 1;
+    }
+    return 0;
+}
+
+/* return the value for option -<opt> ("-n 5" or "-n5"), or 0 if absent */
+char *optval(char **argv, unsigned char argc, char opt) {
+    unsigned char i;
+    for (i = 0; i < argc; i++) {
+        if (argv[i][0] == '-' && argv[i][1] == opt) {
+            if (argv[i][2]) return &argv[i][2];
+            if (i + 1 < argc) return argv[i+1];
+            return 0;
+        }
+    }
+    return 0;
+}