i/o redirection in sh

better parsing of sh commands (copied from jos sh)
cat: read from 1 if no args
sbrk system call, but untested
getpid system call
moved locks in keyboard intr, but why do we get intr w. null characters from keyboard?

1 files changed, 17 insertions, 0 deletions

diff --git a/ulib.c b/ulib.c
index 004b934..c6c7f19 100644
--- a/ulib.c
+++ b/ulib.c
@@ -20,6 +20,14 @@ strcpy(char *s, char *t)
 	return os;
 }
 
+int
+strcmp(const char *p, const char *q)
+{
+	while (*p && *p == *q)
+		p++, q++;
+	return (int) ((unsigned char) *p - (unsigned char) *q);
+}
+
 unsigned int
 strlen(char *s)
 {
@@ -41,6 +49,15 @@ memset(void *dst, int c, unsigned int n)
 }
 
 char *
+strchr(const char *s, char c)
+{
+	for (; *s; s++)
+		if (*s == c)
+			return (char *) s;
+	return 0;
+}
+
+char *
 gets(char *buf, int max)
 {
   int i = 0, cc;