improved error handling and ignorance of trailing ws

2 files changed, 32 insertions, 9 deletions

diff --git a/README b/README
index 1815214..843ffbf 100644
--- a/README
+++ b/README
@@ -47,4 +47,6 @@ It mostly segfaults on line overfill (i.e. trying to center oversized
 text or unfoldable lines are completely unhandled). Error handling
 should probably be used, but that is a nontrivial addition.
 
-Nonexistent commands also cause segfaults.
+# Return Value
+
+Returns 0 on success and 1 on syntax error.
diff --git a/badroff.c b/badroff.c
index 213a9c9..66fce40 100644
--- a/badroff.c
+++ b/badroff.c
@@ -2,6 +2,7 @@
 #include <string.h>
 #include <stdlib.h>
 #include <stdbool.h>
+#include <ctype.h>
 
 #include "buf.h"
 #include "sb.h"
@@ -69,8 +70,15 @@ size_t chrnfill(char chr, size_t sz){//fills to first of chr or sz
 static int width = 80;
 static char nbsp = 0;
 
+static char* strdup(char* str){
+    char* out = malloc(sizeof(char)*(strlen(str)+1));
+    strcpy(out,str);
+    return out;
+}
+
 static char* center(char* txt){
-    size_t len = strlen(txt);
+    int len = strlen(txt);
+    if (len >= width) return strdup(txt);
     int max = width/2 + len/2; // excluding terminator
     int min = max-len+1; // first index of *txt
     char* str = malloc(sizeof(char)*(max + 2));
@@ -96,10 +104,16 @@ static char* token(char* txt, char c) {
     return end+1;
 }
 static char* leader(char* txt){
-    char* start = txt;
-    char* repeat = token(start, '|');
-    char* end = token(repeat, '|');
-    char* fin = malloc(sizeof(char)*(width+2));
+    char *start, *repeat, *end, *fin;
+    start = txt;
+    if ( !(repeat = token(start, '|') ) ) {
+        repeat = " . ";
+        end = "";
+    } else if ( !(end = token(repeat, '|') ) ) {
+        repeat = " . ";
+        end = repeat;
+    }
+    fin = malloc(sizeof(char)*(width+2));
     fin[width] = '\n'; fin[width+1] = 0;
     strcpy(fin, start);
     size_t max = width-strlen(end); size_t rptln = strlen(repeat);
@@ -206,7 +220,7 @@ static char* fingroup(char* txt){
     return emptalloc();
 }
 static char* vert(char* txt){
-    int ln; sscanf(txt, "%d", &ln);
+    int ln; if (isdigit(*txt)) sscanf(txt, "%d", &ln); else ln = 1;
     return chrmult('\n', ln);
 }
 static char* nbrkspc(char* txt){
@@ -255,8 +269,9 @@ static char* (*call[])(char* txt) =
 
 static char* cmd(void){
     char* dat = popstrbuf(inbuf, chrfill('\n'));
-    size_t low = 0; size_t high = sizeof(cmds)/sizeof(*cmds); //len
+    int low = 0; int high = sizeof(cmds)/sizeof(*cmds); //len
     char* proc = NULL;
+    bool found = false;
     while (high >= low){
         int mid = ((unsigned int)low + (unsigned int)high) >> 1;
         char* mval = cmds[mid];
@@ -267,12 +282,17 @@ static char* cmd(void){
         else if (cmp > 0)
             low = mid + 1;
         else{
+            found = true;
             proc = call[mid](dat+strlen(mval));
             break;
         }
     }
     free(dat);
-    return proc;
+    if (found) return proc;
+    else {
+        fprintf(stderr, "SYNTAX ERROR\n");
+        exit(1);
+    }
 }
 
 // normal typesetting 
@@ -345,6 +365,7 @@ char* line(void){
         out = norm();
     }
     nbspsub(out);
+    wsclean(out);
     return out;
 }