added help

diff.c

@@ -7,37 +7,17 @@
 
 // ================================================================ //
 
-void init(int argc, const char* argv[]);
-void setoption(const char* arg, const char* s, const char* t, int* value);
-void diff_output_conflict_error(void);
-
-void loadfiles(const char* filename1, const char* filename2);
-
-void version();
-void todo();
-
-int normal(const char* filename1, const char* filename2);
-int sideside(const char* filename1, const char* filename2);
-void quiet(const char* filename1, const char* filename2);
-void loud(const char* filename1, const char* filename2);
-
-// ================================================================ //
-
 int main(int argc, const char* argv[]) {
 
   init(--argc, ++argv);
   loadfiles(files[0], files[1]);
 
   if (**argv != '-')      { normal(files[0], files[1]); }
-  if (argc < 3)           { printf("Usage: ./diff [options] file1 file2\n"); }
 
-  //if (!diffnormal)         { normal(files[0], files[1]); printf("\n"); }
   if (showsidebyside)     { sideside(files[0], files[1]); }
   if (showbrief)          { quiet(files[0], files[1]); }
   if (report_identical)   { loud(files[0], files[1]); }
-  if (!showversion && !showbrief && !ignorecase && !report_identical &&
+
-      !diffnormal && !showsidebyside && !showleftcolumn && !suppresscommon &&
-      !showcontext && !showunified && !showhelp) { printf("Usage: ./diff [options] file1 file2\n"); }
   return 0;
 
 }
@@ -70,7 +50,10 @@ void init(int argc, const char* argv[]) {
     ++argv;
   }
 
+  // ================================= //
+
   if (showversion)                                       { version();  exit(0); }
+  if (showhelp)                                          { help();     exit(0); }
 
   if (!showcontext && !showunified &&
       !showsidebyside && !showleftcolumn)                { diffnormal = 1; }
@@ -95,6 +78,8 @@ void diff_output_conflict_error(void) {
 
 void loadfiles(const char* filename1, const char* filename2) {
 
+  if (filename2 == NULL) { printf("Usage: ./diff [options] file1 file2\n"); exit(1); }
+
   memset(buf, 0, sizeof(buf));
   memset(strings1, 0, sizeof(strings1));
   memset(strings2, 0, sizeof(strings2));
@@ -108,8 +93,6 @@ void loadfiles(const char* filename1, const char* filename2) {
   p = pa_first(strings1, count1);
   q = pa_first(strings2, count2);
 
-  int foundmatch = 0;
-
 }
 
 void version() {
@@ -132,25 +115,38 @@ void version() {
   printf("Any unauthorized use or re-distribution of this code is permitted.\n\n");
   printf("\tChris Nutter\tWilliam McCarthy    Rasputin\n\n\n");
 }
-void todo() {
+void help() {
-  printf("\nTODO: check line by line in a pagraph, using '|' for differences");
+  printf("\nUsage: diff-rcm [OPTION]... FILES\n");
-  printf("\nTODO: this starter code does not yet handle printing all of fin1's pagraphs.");
+  printf("Compare FILES line by line.\n\n");
-  printf("\nTODO: handle the rest of diff's options");
+  printf("Mandatory arguments to long options are mandatory for short options too.\n\n");
-  printf("\nTODO: fix standard printing with no pameters");
+  printf("\t    --normal\t\t        output a normal diff (the default)\n");
-  printf("\nTODO: implement multiple types of pameters\n");
+  printf("\t-q, --brief\t\t        report only when files differ\n");
+  printf("\t-s, --report-identical-files    report when two files are the same\n");
+  printf("\t-c, -C NUM, --context[=NUM]     output NUM (default 3) lines of copied context\n");
+  printf("\t-u, -U NUM, --unified[=NUM]     output NUM (default 3) lines of unified context\n");
+  printf("\t-y, --side-by-side\t        output in two columns\n\n");
+  printf("\t-i, --ignore-case\t        ignore case differences in file contents\n\n");
+  printf("\t    --help\t\t        display this help and exit\n");
+  printf("\t-v, --version\t\t        output version information and exit\n\n");
+
+  printf("FILES are 'FILE1 FILE2'\n");
+  printf("If --from-file or --to-file is given, there are no restrictions on FILE(s).\n");
+  printf("If a FILE is '-', read standard input.\n");
+  printf("Exit status is 0 if inputs are the same, 1 if different, 2 if trouble.\n\n");
+  printf("Report bugs to: cdnutter@gmail.com\n");
+  printf("diff-rcm homepage: <https://www.github.com/cdnutter/diff/>\n\n");
 }
 
 int normal(const char* filename1, const char* filename2) {
 
   printf("\nTHIS IS NOT NORMAL FOR NOW. THIS IS PLACEHOLDER. MMKAY.\n");
+  printf("THIS IS NOT NORMAL FOR NOW. THIS IS PLACEHOLDER. MMKAY.\n");
+  printf("THIS IS NOT NORMAL FOR NOW. THIS IS PLACEHOLDER. MMKAY.\n");
   printf("THIS IS NOT NORMAL FOR NOW. THIS IS PLACEHOLDER. MMKAY.\n\n\n");
 
   pa_print(p, printleft);
   pa_print(q, printright);
 
-  printf("\nTHIS IS NOT NORMAL FOR NOW. THIS IS PLACEHOLDER. MMKAY.\n");
-  printf("THIS IS NOT NORMAL FOR NOW. THIS IS PLACEHOLDER. MMKAY.\n\n\n");
-
   return 0;
 }
 int sideside(const char* filename1, const char* filename2) {
@@ -162,7 +158,7 @@ int sideside(const char* filename1, const char* filename2) {
 
   return 0;
 }
-void quiet(const char* filename1, const char* filename2) { if (pa_equal(p, q) == 0) { printf("The files are not the same.\n"); } }
+void quiet(const char* filename1, const char* filename2) { if (pa_equal(p, q) == 0) { printf("The files are not the same.\n"); } else { return; } }
 void loud(const char* filename1, const char* filename2) {
 
   if (pa_equal(p, q) != 0) { printf("The files are equal.\n"); }
@@ -171,3 +167,11 @@ void loud(const char* filename1, const char* filename2) {
 }
 
 // ================================================================ //
+
+/*
+    TODO: check line by line in a pagraph, using '|' for differences");
+    TODO: this starter code does not yet handle printing all of fin1's pagraphs.");
+    TODO: handle the rest of diff's options");
+    TODO: fix standard printing with no pameters");
+    TODO: implement multiple types of pameters\n");
+*/

diff.h

@@ -12,7 +12,7 @@
 #define HASHLEN 200
 #define BUFLEN 256
 
-// ======================================================================= //
+// ================================================================= //
 
 FILE *fin1, *fin2;
 const char* files[2] = { NULL, NULL };
@@ -27,3 +27,19 @@ int showhelp = 0;
 int equal = 0, cnt = 0, count = 0;
 
 int count1 = 0, count2 = 0;
+
+// ================================================================ //
+
+void init(int argc, const char* argv[]);
+void setoption(const char* arg, const char* s, const char* t, int* value);
+void diff_output_conflict_error(void);
+
+void loadfiles(const char* filename1, const char* filename2);
+
+void version();
+void help();
+
+int normal(const char* filename1, const char* filename2);
+int sideside(const char* filename1, const char* filename2);
+void quiet(const char* filename1, const char* filename2);
+void loud(const char* filename1, const char* filename2);

helptxt.txt

@@ -0,0 +1,23 @@
+Usage: diff-rcm [OPTION]... FILES
+Compare FILES line by line.
+
+Mandatory arguments to long options are mandatory for short options too.
+      --normal                  output a normal diff (the default)
+  -q, --brief                   report only when files differ
+  -s, --report-identical-files  report when two files are the same
+  -c, -C NUM, --context[=NUM]   output NUM (default 3) lines of copied context
+  -u, -U NUM, --unified[=NUM]   output NUM (default 3) lines of unified context
+  -y, --side-by-side            output in two columns
+
+  -i, --ignore-case               ignore case differences in file contents
+
+      --help               display this help and exit
+  -v, --version            output version information and exit
+
+FILES are 'FILE1 FILE2'
+If --from-file or --to-file is given, there are no restrictions on FILE(s).
+If a FILE is '-', read standard input.
+Exit status is 0 if inputs are the same, 1 if different, 2 if trouble.
+
+Report bugs to: cdnutter@gmail.com
+diff-rcm home page: <https://Github.com/cdnutter/diff/>

pa.c

@@ -29,6 +29,7 @@ pa* pa_next(pa* p) {
 
   return pnew;
 }
+
 void pa_print(pa* p, void (*fp)(const char*)) {
   if (p == NULL) { return; }
   for (int i = p->start; i <= p->stop && i != p->filesize; ++i) { fp(p->base[i]); }
@@ -55,16 +56,19 @@ void printboth(const char* left_right) {
   buf[len - 1] = '\0';
   printf("%-50s %s", buf, left_right);
 }
+
 size_t pa_filesize(pa* p) { return p == NULL ? 0 : p->filesize; }
 size_t pa_size(pa* p) { return p == NULL || p->stop < p->start ? 0 : p->stop - p->start + 1; }
+
 char** pa_base(pa* p) { return p->base; }
-//char* yesorno(int condition) { return condition == 0 ? "no" : "YES"; }
+char* yesorno(int condition) { return condition == 0 ? "no" : "YES"; }
 char* pa_info(pa* p) {
   static char buf[BUFLEN];   // static for a reason
   snprintf(buf, sizeof(buf), "base: %p, filesize: %d, start: %d, stop: %d\n",
     p->base, p->filesize, p->start, p->stop);
   return buf;  // buf MUST be static
 }
+
 int pa_equal(pa* p, pa* q) {
   if (p == NULL || q == NULL) { return 0; }
   if (pa_size(p) != pa_size(q)) { return 0; }
@@ -72,6 +76,7 @@ int pa_equal(pa* p, pa* q) {
   while ((equal = strcmp(p->base[i], q->base[i])) == 0) { ++i; ++j; }
   return equal;
 }
+
 FILE* openfile(const char* filename, const char* openflags) {
   FILE* f;
   if ((f = fopen(filename, openflags)) == NULL) {  printf("can't open '%s'\n", filename);  exit(1); }