slight refactor and start documenting

1 files changed, 57 insertions, 32 deletions

diff --git a/command/cat.c b/command/cat.c
index f88ca28..8a87369 100644
--- a/command/cat.c
+++ b/command/cat.c
@@ -1,27 +1,28 @@
+/**
+ *  file: cat.c
+ *  author: Tyler Murphy
+ */
+
 #include "command.h"
 #include "lslib.h"
 
 #include <ctype.h>
 #include <stdlib.h>
 
+/**
+ * Flags that are to be used with cat
+ */
 static struct {
-    bool number_lines;
-    bool number_non_empty;
-    bool change_non_print;
-    bool change_tabs;
-    bool end_lines_dollar;
+    bool number_lines;      /* if to number the lines */
+    bool number_non_empty;  /* if to number empty lines */
+    bool change_non_print;  /* if to change non printable characters to be printable */
+    bool change_tabs;       /* if to change tabs to ^I */
+    bool end_lines_dollar;  /* if to print a $ at the end of lines */
 } flags;
 
-static bool printable(char c) {
-    switch (c) {
-        case '\n': return true;
-        case '\r': return true;
-        case '\b': return true;
-        case '\t': return true;
-        default: return isprint(c) == 0;
-    }
-}
-
+/**
+ * Help function for cat
+ */
 static void help(void) {
     printf("Usage: cat [-nbvteA] [FILE]...\n\n");
     printf("Print FILEs to stdout\n\n");
@@ -33,52 +34,68 @@ static void help(void) {
     printf("\t-A	Same as -vte\n");
 }
 
+/**
+ * Give a file pointer, cat all its contents
+ * @param file the file to cat
+ */
 static void cat_file(FILE* file) {
-    char c;
-    size_t read;
+    char c; /* current character read */
+    size_t read; /* amount read */
     
-    size_t line = 1;
-    bool empty = true;
-    bool newline = true;
+    /* default arguments */
+    size_t line = 1; /* what line we are on, 1 indexed */
+    bool empty = true; /* if the current line is empty (nothing printed) */
+    bool newline = true; /* if we are on a new line */
     
+    /* read file a character at a time */
     while ((read = fread(&c, 1, 1, file)) != 0) {
+        /* if its a new line, update the new line pointer */
         if (c == '\n') {
-            if (empty && flags.number_lines) {
+            if (empty && flags.number_lines) { /* print line number if set to */
                 printf("\t%ld ", line);
             }
-            if (flags.end_lines_dollar) {
+            if (flags.end_lines_dollar) { /* pint $ if set to */
                 printf("$");
             }
             line++;
-            newline = true;
-            empty = true;
+            newline = true; /* tell that the new line number is set to be printed */
+            empty = true; /* set line to empty */
             goto print;
         } else {
             empty = false;
         }
-
+        
+        /* skip next check if not newline */
         if (!newline) {
             goto print;
         }
 
+        /* if on a new line and is a valid char, print line number */
         if (!empty && (flags.number_non_empty || flags.number_lines)) {
             printf("\t%ld ", line);
             newline = false;
         }
     print:
-        if (!flags.change_non_print || printable(c)) {
+        /* print character */
+        if (!flags.change_non_print || printable_char(c)) {
             if (flags.change_tabs && c == '\t') {
-                fwrite("^I", 1, 2, stdout);
+                fwrite("^I", 1, 2, stdout); /* print ^I instead of tab */
             } else {
-                fwrite(&c, 1, 1, stdout);
+                fwrite(&c, 1, 1, stdout); /* print character to stdout */
             }
-        } else {
+        } else { /* if set to change non print, fix char code */
             c |= '@';
             fwrite(&c, 1, 1, stdout);
         }
     }
 }
 
+/** 
+ * Takes in each argument that has a single - and parses it 
+ * @param c the character after the -
+ * @param next the next argument in argv that hasnt been parsed
+ * @reutrn if the next arg was used or if the arg was invalid
+ */
 static int short_arg(char c, char* next) {
     UNUSED(next);
     switch (c) {
@@ -110,33 +127,41 @@ static int short_arg(char c, char* next) {
     return ARG_UNUSED;
 }
 
+/**
+ * Output a files contents
+ */
 COMMAND(cat_main) {
 
     int start;
     int arg_len;
     int i;
 
+    /* set flag defaults */
     flags.number_lines = false;
     flags.number_non_empty = false;
     flags.change_non_print = false;
     flags.change_tabs = false;
     flags.end_lines_dollar = false;
 
+    /* parse user arguments */
     start = parse_args(argc, argv, help, short_arg, NULL);
 
+    /* get the number of arguments to cat */
     arg_len = argc - start;
 
+    /* if not read from stdin */
     if (arg_len < 1) {
         cat_file(stdin);
         return EXIT_SUCCESS;
     }
 
+    /* foreach file, try to open it, and then cat it */
     for (i = start; i < argc; i++) {
-        FILE* in = get_file(argv[i], "r");
-        cat_file(in);
+        FILE* in = get_file(argv[i], "r"); /* open file as read */
+        cat_file(in); /* print it out */
         if (in != stdin)
             fclose(in);
     }
 
-    return EXIT_SUCCESS;
+    return EXIT_SUCCESS; /* success */
 }