Created student weenix repository

1 files changed, 114 insertions, 0 deletions

diff --git a/user/usr/bin/wc.c b/user/usr/bin/wc.c
new file mode 100644
index 0000000..f622614
--- /dev/null
+++ b/user/usr/bin/wc.c
@@ -0,0 +1,114 @@
+#include <ctype.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#define BUFFER_SIZE 1024
+
+typedef struct count_results
+{
+    unsigned long long n_chars;
+    unsigned long long n_words;
+    unsigned long long n_lines;
+} count_results_t;
+
+char buf[BUFFER_SIZE];
+
+void print_counts(count_results_t *results, char *name)
+{
+    if (name)
+    {
+        printf("%10llu %10llu %10llu %10s\n", results->n_lines,
+               results->n_words, results->n_chars, name);
+    }
+    else
+    {
+        printf("%10llu %10llu %10llu\n", results->n_lines, results->n_words,
+               results->n_chars);
+    }
+}
+
+void count(int fd, char *name, count_results_t *results)
+{
+    size_t bytes_read;
+    unsigned int in_word, i;
+
+    in_word = 0;
+    while ((bytes_read = read(fd, buf, BUFFER_SIZE)) > 0)
+    {
+        for (i = 0; i < bytes_read; ++i)
+        {
+            if (isspace(buf[i]))
+            {
+                if (in_word)
+                {
+                    results->n_words++;
+                    in_word = 0;
+                }
+            }
+            else
+            {
+                in_word = 1;
+            }
+
+            if (buf[i] == '\n')
+            {
+                results->n_lines++;
+            }
+        }
+
+        results->n_chars += bytes_read;
+    }
+
+    print_counts(results, name);
+}
+
+int main(int argc, char **argv)
+{
+    int f, fd;
+    count_results_t total_counts = {.n_chars = 0, .n_words = 0, .n_lines = 0};
+    count_results_t local_counts = {.n_chars = 0, .n_words = 0, .n_lines = 0};
+
+    if (argc == 1)
+    {
+        /* Reading from standard input. */
+        count(0, 0, &total_counts);
+    }
+    else
+    {
+        /* Reading files, not standard input. */
+        for (f = 1; f < argc; ++f)
+        {
+            fd = open(argv[f], O_RDONLY, 0);
+            if (fd < 0)
+            {
+                /* Error opening file. */
+                fprintf(stderr, "wc: %s: open: %s\n", argv[f], strerror(errno));
+            }
+            else
+            {
+                /* Opened the file. */
+                count(fd, argv[f], &local_counts);
+
+                total_counts.n_chars += local_counts.n_chars;
+                total_counts.n_words += local_counts.n_words;
+                total_counts.n_lines += local_counts.n_lines;
+
+                /* Reset the local counts. */
+                local_counts.n_chars = local_counts.n_words =
+                    local_counts.n_lines = 0;
+
+                close(fd);
+            }
+        }
+
+        if (argc > 2)
+        {
+            /* They provided multiple files. We should print the total too. */
+            print_counts(&total_counts, "total");
+        }
+    }
+
+    return 0;
+}