lab util: finishutil

7 files changed, 292 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index 365c91b..4f3fd54 100644
--- a/Makefile
+++ b/Makefile
@@ -188,6 +188,11 @@ UPROGS=\
 	$U/_grind\
 	$U/_wc\
 	$U/_zombie\
+	$U/_sleep\
+	$U/_pingpong\
+	$U/_primes\
+	$U/_find\
+	$U/_xargs\
 
 
 
diff --git a/user/find.c b/user/find.c
new file mode 100644
index 0000000..e185e9d
--- /dev/null
+++ b/user/find.c
@@ -0,0 +1,84 @@
+#include "kernel/types.h"
+
+#include "kernel/fcntl.h"
+#include "kernel/fs.h"
+#include "kernel/stat.h"
+#include "user/user.h"
+
+char*
+fmtname(char* path)
+{
+  char* p;
+
+  // Find first character after last slash.
+  for (p = path + strlen(path); p >= path && *p != '/'; p--)
+    ;
+  p++;
+  return p;
+}
+
+void
+find(char* root_path, char* filename)
+{
+  static char buf[512];
+  char* p;
+  int fd;
+  struct dirent de;
+  struct stat st;
+
+  if ((fd = open(root_path, O_RDONLY)) < 0) {
+    fprintf(2, "find: cannot open %s\n", root_path);
+    return;
+  }
+  if (fstat(fd, &st) < 0) {
+    fprintf(2, "find: cannot stat %s\n", root_path);
+    close(fd);
+    return;
+  }
+
+  switch (st.type) {
+    case T_FILE:
+      if (!strcmp(fmtname(root_path), filename)) {
+        printf("%s\n", root_path);
+      }
+      break;
+    case T_DIR:
+      if (strlen(root_path) + 1 + DIRSIZ + 1 > sizeof(buf)) {
+        printf("find: path too long\n");
+        break;
+      }
+
+      strcpy(buf, root_path);
+
+      p = buf + strlen(buf);
+      *p++ = '/';
+      while (read(fd, &de, sizeof(de)) == sizeof(de)) {
+        if (de.inum == 0)
+          continue;
+        memmove(p, de.name, DIRSIZ);
+        p[DIRSIZ] = '\0';
+
+        // printf("i'm finding %s!\n", fmtname(buf));
+
+        if (!strcmp(fmtname(buf), ".") || !strcmp(fmtname(buf), "..")) {
+          continue;
+        }
+
+        find(buf, filename);
+      }
+  }
+  close(fd);
+}
+
+int
+main(int argc, char* argv[])
+{
+  if (argc < 3) {
+    fprintf(2, "usage: find [root_path] filename...\n");
+    exit(1);
+  }
+
+  for (int i = 2; i < argc; i++) {
+    find(argv[1], argv[i]);
+  }
+}
diff --git a/user/pingpong.c b/user/pingpong.c
new file mode 100644
index 0000000..7b03a76
--- /dev/null
+++ b/user/pingpong.c
@@ -0,0 +1,44 @@
+#include "kernel/types.h"
+#include "user/user.h"
+
+int
+main(int argc, char* argv[])
+{
+  int p[2];
+
+  if (argc > 1) {
+    fprintf(2, "usage: pingpong\n");
+    exit(1);
+  }
+
+  pipe(p);
+
+  int pid = fork();
+
+  if (pid == 0) {
+    short n;
+    read(p[0], &n, sizeof(n));
+    if (n == 42) {
+      fprintf(1, "%d: received ping\n", getpid());
+    }
+    n++;
+    write(p[1], &n, sizeof(n));
+    close(p[0]);
+    close(p[1]);
+    exit(0);
+  }
+
+  short n = 42;
+
+  write(p[1], &n, sizeof(n));
+  read(p[0], &n, sizeof(n));
+  if (n == 43) {
+    fprintf(1, "%d: received pong\n", getpid());
+  }
+  close(p[0]);
+  close(p[1]);
+
+  wait(0);
+
+  exit(0);
+}
diff --git a/user/primes.c b/user/primes.c
new file mode 100644
index 0000000..b359524
--- /dev/null
+++ b/user/primes.c
@@ -0,0 +1,74 @@
+#include "kernel/types.h"
+#include "user/user.h"
+
+#define MAX 36
+#define FIRST_PRIME 2
+
+int
+generate_natural(); // -> out_fd
+int
+prime_filter(int in_fd, int prime); // -> out_fd
+
+int
+main(int argc, char* argv[])
+{
+  int prime;
+
+  int in = generate_natural();
+  while (read(in, &prime, sizeof(int))) {
+    // printf("prime %d: in_fd: %d\n", prime, in);  // debug
+    printf("prime %d\n", prime);
+    in = prime_filter(in, prime);
+  }
+
+  close(in);
+
+  exit(0);
+}
+
+int
+generate_natural()
+{
+  int out_pipe[2];
+
+  pipe(out_pipe);
+
+  if (!fork()) {
+    for (int i = FIRST_PRIME; i < MAX; i++) {
+      write(out_pipe[1], &i, sizeof(int));
+    }
+    close(out_pipe[1]);
+
+    exit(0);
+  }
+
+  close(out_pipe[1]);
+
+  return out_pipe[0];
+}
+
+int
+prime_filter(int in_fd, int prime)
+{
+  int num;
+  int out_pipe[2];
+
+  pipe(out_pipe);
+
+  if (!fork()) {
+    while (read(in_fd, &num, sizeof(int))) {
+      if (num % prime) {
+        write(out_pipe[1], &num, sizeof(int));
+      }
+    }
+    close(in_fd);
+    close(out_pipe[1]);
+
+    exit(0);
+  }
+
+  close(in_fd);
+  close(out_pipe[1]);
+
+  return out_pipe[0];
+}
diff --git a/user/sh.c b/user/sh.c
index 836ebcb..5eceda0 100644
--- a/user/sh.c
+++ b/user/sh.c
@@ -165,6 +165,9 @@ main(void)
         fprintf(2, "cannot cd %s\n", buf+3);
       continue;
     }
+    if(buf[0] == 'e' && buf[1] == 'x' && buf[2] == 'i' && buf[3] == 't'){
+      exit(0);
+    }
     if(fork1() == 0)
       runcmd(parsecmd(buf));
     wait(0);
diff --git a/user/sleep.c b/user/sleep.c
new file mode 100644
index 0000000..961f558
--- /dev/null
+++ b/user/sleep.c
@@ -0,0 +1,22 @@
+#include "kernel/types.h"
+#include "user/user.h"
+
+int
+main(int argc, char* argv[])
+{
+  uint sec = 0;
+
+  if (argc <= 1) {
+    fprintf(2, "usage: sleep [time (ticks)]\n");
+    exit(1);
+  }
+  sec = atoi(argv[1]);
+
+  sleep(sec);
+
+  if (argc <= 2) {
+    exit(0);
+  }
+
+  exit(0);
+}
diff --git a/user/xargs.c b/user/xargs.c
new file mode 100644
index 0000000..b5b9bee
--- /dev/null
+++ b/user/xargs.c
@@ -0,0 +1,60 @@
+#include "kernel/types.h"
+
+#include "kernel/param.h"
+#include "kernel/stat.h"
+#include "user/user.h"
+
+#define is_blank(chr) (chr == ' ' || chr == '\t')
+
+int
+main(int argc, char* argv[])
+{
+  char buf[2048], ch;
+  char* p = buf;
+  char* v[MAXARG];
+  int c;
+  int blanks = 0;
+  int offset = 0;
+
+  if (argc <= 1) {
+    fprintf(2, "usage: xargs <command> [argv...]\n");
+    exit(1);
+  }
+
+  for (c = 1; c < argc; c++) {
+    v[c - 1] = argv[c];
+  }
+  --c;
+
+  while (read(0, &ch, 1) > 0) {
+    if (is_blank(ch)) {
+      blanks++;
+      continue;
+    }
+
+    if (blanks) {
+      buf[offset++] = 0;
+
+      v[c++] = p;
+      p = buf + offset;
+
+      blanks = 0;
+    }
+
+    if (ch != '\n') {
+      buf[offset++] = ch;
+    } else {
+      v[c++] = p;
+      p = buf + offset;
+
+      if (!fork()) {
+        exit(exec(v[0], v));
+      }
+      wait(0);
+
+      c = argc - 1;
+    }
+  }
+
+  exit(0);
+}