add yenc

CHANGES

@@ -1,10 +1,6 @@
 0.12:
   add textcode api for uuencode/uudecode, base64, quoted printable,
     url-encoding and yenc.
-  implement fmt_uuencoded and scan_uuencoded.
-  implement fmt_base64, scan_base64.
-  implement fmt_quotedprintable, scan_quotedprintable
-  implement fmt_urlencoded, scan_urlencoded
 
 0.11:
   fix fmt_long (didn't count the '-'), which in turn broke

t.c

@@ -17,19 +17,30 @@
      __asm__ __volatile__ ("rdtsc" : "=a" (low) : : "edx")
 
 int main(int argc,char* argv[]) {
+  unsigned long size;
+  char* buf=mmap_read(argv[1],&size);
+  if (buf) {
+    unsigned int x=fmt_yenc(0,buf,size);
+    unsigned int y;
+    char* tmp=malloc(x+1);
+    y=fmt_yenc(tmp,buf,size);
+    write(1,tmp,x);
+  }
+#if 0
   char buf[100];
   char buf2[100];
   unsigned int len,len2;
-  buf[fmt_urlencoded(buf,"http://localhost/~fefe",22)]=0;
+  buf[fmt_yenc(buf,"http://localhost/~fefe",22)]=0;
   buffer_puts(buffer_1,buf);
   buffer_putsflush(buffer_1,"\n");
-  if ((buf[len2=scan_urlencoded(buf,buf2,&len)])!=0) {
+  if ((buf[len2=scan_yenc(buf,buf2,&len)])!='\n') {
     buffer_putsflush(buffer_2,"parse error!\n");
     return 1;
   }
   buffer_put(buffer_1,buf2,len2);
   buffer_putsflush(buffer_1,"\n");
   return 0;
+#endif
 #if 0
   char buf[100];
   char buf2[100];

textcode/fmt_yenc.c

@@ -0,0 +1,41 @@
+#include "fmt.h"
+#include "textcode.h"
+
+unsigned int fmt_yenc(char* dest,const char* src,unsigned int len) {
+  register const unsigned char* s=(const unsigned char*) src;
+  unsigned long written=0,i;
+  int linelen=0;
+  for (i=0; i<len; ++i) {
+    unsigned char c=s[i]+42;
+    switch (c) {
+    case ' ':	/* escape space at line ending */
+      if (linelen==253) {
+	if (dest) dest[written]='\n'; ++written; linelen=0;
+      }
+      goto dontescape;
+    case 'F':	/* escape "^From " */
+      if (s[i+1]+42!='r' || s[i+2]+42!='o' || s[i+3]+42!='m' || s[i+4]+42!=' ') goto dontescape;
+    case '.':	/* dot at start of line needs to be escaped */
+      if (!linelen) goto dontescape;
+      /* fall through */
+    case 0:
+    case '\n':
+    case '\r':
+    case '=':
+      if (dest) dest[written]='='; ++written;
+      c+=64;
+      /* fall through */
+    default:
+dontescape:
+      ++linelen;
+      if (dest) dest[written]=c; ++written;
+      if (linelen>253) {
+	if (dest) dest[written]='\n'; ++written; linelen=0;
+      }
+    }
+  }
+  if (linelen) {
+    if (dest) dest[written]='\n'; ++written; linelen=0;
+  }
+  return written;
+}

textcode/scan_yenc.c

@@ -0,0 +1,20 @@
+#include "fmt.h"
+#include "textcode.h"
+
+unsigned int scan_yenc(const char *src,char *dest,unsigned int *destlen) {
+  register const unsigned char* s=(const unsigned char*) src;
+  unsigned long written=0,i;
+  for (i=0; s[i]; ++i) {
+    if (s[i]=='=') {
+      ++i;
+      if (s[i]=='y') break;
+      dest[written]=s[i]-64-42;
+    } else if (s[i]=='\n' || s[i]=='\r' || s[i]=='\0')
+      break;
+    else
+      dest[written]=s[i]-42;
+    ++written;
+  }
+  *destlen=written;
+  return i;
+}