1 files changed, 161 insertions, 0 deletions
diff --git a/src/commands/wc.c b/src/commands/wc.c
new file mode 100644
index 0000000..7132370
--- /dev/null
+++ b/src/commands/wc.c
@@ -0,0 +1,161 @@
+#include "../command.h"
+
+#include <ctype.h>
+#include <stdio.h>
+#include <string.h>
+
+struct Flags {
+    bool newlines;
+    bool words;
+    bool characters;
+    bool bytes;
+    bool longest_line;
+};
+
+static int lines = 0;
+static int words = 0;
+static int chars = 0;
+static int bytes = 0;
+static int logst = 0;
+
+static void list(int l, int w, int c, int b, int lg, struct Flags* flags) {
+    if (flags->newlines) {
+        printf("\t%d", l);
+    }
+    if (flags->words) {
+        printf("\t%d", w);
+    }
+    if (flags->characters) {
+        printf("\t%d", c);
+    }
+    if (flags->bytes) {
+        printf("\t%d", b);
+    }
+    if (flags->longest_line) {
+        printf("\t%d", lg);
+    }
+}
+
+#define BS 1024
+
+static bool is_delimiter(char c) {
+    return c == ' ' || c == '\t' || c == '\n';
+}
+
+static void run_wc(FILE* file, struct Flags* flags) {
+    int l = 0, w = 0, c = 0, b = 0, lg = 0;
+
+    bool in_word = false;
+    int current_length = 0;
+
+    int read;
+    char buf[BS];
+    while ((read = fread(buf, 1, 1024, file)) > 0) {
+        for (int i = 0; i < read; i++) {
+            char ch = buf[i];
+            b++;
+            if (ch == '\n') { 
+                l++;
+                lg = lg > current_length ? lg : current_length;
+                current_length = 0;
+            } else {
+                current_length++;
+            }
+            if (isprint(ch) || is_delimiter(ch)) c++;
+            if (in_word && is_delimiter(ch)) {
+                in_word = false;
+                w++;
+            } else if (!in_word && !is_delimiter(ch) && isprint(ch)) {
+                in_word = true;
+            }
+        }
+    }
+    if (in_word) w++;
+    lg = lg > current_length ? lg : current_length;
+    list(l, w, c, b, lg, flags);
+    lines += l;
+    words += w;
+    chars += c;
+    bytes += b;
+    logst += lg;
+    if (file != stdin)
+        fclose(file);
+}
+
+static void help() {
+    printf("Usage: wc [-cmlwL] [FILE]...\n\n");
+    printf("Count lines, words, and bytes for FILEs (or stdin)\n\n");
+	printf("\t-c	Count bytes\n");
+	printf("\t-m	Count characters\n");
+	printf("\t-l	Count newlines\n");
+	printf("\t-w	Count words\n");
+	printf("\t-L	Print longest line length\n");
+    exit(EXIT_SUCCESS);
+}
+
+COMMAND(wc) {
+    struct Flags flags;
+    flags.newlines = false;
+    flags.words = false;
+    flags.characters = false;
+    flags.bytes = false;
+    flags.longest_line = false;
+
+    bool has_flags = false;
+
+    int start = 0;
+    for (int i = 0; i < argc; i++) {
+        if (!prefix("-", argv[i])) break;
+        if (streql("--help", argv[i])) help();
+
+        start++;
+        for (size_t j = 1; j < strlen(argv[i]); j++) {
+            char c = argv[i][j];
+            switch (c) {
+                case 'c':
+                    flags.bytes = true;
+                    break;
+                case 'm':
+                    flags.characters = true;
+                    break;
+                case 'l':
+                    flags.newlines = true;
+                    break;
+                case 'w':
+                    flags.words = true;
+                    break;
+                case 'L':
+                    flags.longest_line = true;
+                    break;
+                default:
+                    error("error: invald option -%c", c);
+            }
+            has_flags = true;
+        }
+    }
+
+    if (!has_flags) {
+        flags.newlines = true;
+        flags.words = true;
+        flags.characters = true;
+    }
+
+    if (argc - start < 1) {
+        run_wc(stdin, &flags);
+        printf("\n");
+        return EXIT_SUCCESS;
+    }
+
+    for (int i = start; i < argc; i++) {
+        FILE* file = get_file(argv[i], "r");
+        run_wc(file, &flags);
+        printf("\t%s\n", argv[i]);
+    }
+
+    if (argc - start > 1) {
+        list(lines, words, chars, bytes, logst, &flags);
+        printf("\ttotal\n");
+    }
+
+    return EXIT_SUCCESS;
+}