library for uniform buffered input.

2 files changed, 164 insertions, 0 deletions

diff --git a/zio.c b/zio.c
new file mode 100644
index 00000000..aa400f7d
--- /dev/null
+++ b/zio.c
@@ -0,0 +1,117 @@
+/*
+* zio.c
+* a generic input stream interface
+* $Id: zio.c,v 1.5 1997/06/13 13:49:16 lhf Exp $
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "zio.h"
+
+#ifdef POPEN
+FILE *popen();
+int pclose();
+#else
+#define popen(x,y) NULL  /* that is, popen always fails */
+#define pclose(x)  (-1)
+#endif
+
+/* ----------------------------------------------------- memory buffers --- */
+
+static int zmfilbuf(ZIO* z)
+{
+ return EOZ;
+}
+
+static int zmclose(ZIO* z)
+{
+ return 1; 
+}
+
+ZIO* zmopen(ZIO* z, char* b, int size)
+{
+ if (b==NULL) return NULL;
+ z->n=size;
+ z->p= (unsigned char *)b;
+ z->filbuf=zmfilbuf;
+ z->close=zmclose;
+ z->u=NULL;
+ return z;
+}
+
+/* ------------------------------------------------------------ strings --- */
+
+ZIO* zsopen(ZIO* z, char* s)
+{
+ if (s==NULL) return NULL;
+ return zmopen(z,s,strlen(s));
+}
+
+/* -------------------------------------------------------------- FILEs --- */
+
+static int zffilbuf(ZIO* z)
+{
+ int n=fread(z->buffer,1,ZBSIZE,z->u);
+ if (n==0) return EOZ;
+ z->n=n-1;
+ z->p=z->buffer;
+ return *(z->p++);
+}
+
+static int zfclose(ZIO* z)
+{
+ if (z->u==stdin) return 0;
+ return fclose(z->u);
+}
+
+ZIO* zFopen(ZIO* z, FILE* f)
+{
+ if (f==NULL) return NULL;
+ z->n=0;
+ z->p=z->buffer;
+ z->filbuf=zffilbuf;
+ z->close=zfclose;
+ z->u=f;
+ return z;
+}
+
+ZIO* zfopen(ZIO* z, char* s, char* m)
+{
+ return zFopen(z,fopen(s,m)); 
+}
+
+/* -------------------------------------------------------------- pipes --- */
+
+static int zpclose(ZIO* z)
+{
+ return pclose(z->u);
+}
+
+ZIO* zpopen(ZIO* z, char* s, char* m)
+{
+ z=zFopen(z,popen(s,m)); 
+ if (z==NULL) return NULL;
+ z->close=zpclose;
+ return z;
+}
+
+/* --------------------------------------------------------------- read --- */
+int zread(ZIO *z, void *b, int n)
+{
+  while (n) {
+    int m;
+    if (z->n == 0) {
+      if (z->filbuf(z) == EOZ)
+        return n;  /* retorna quantos faltaram ler */
+      zungetc(z);  /* poe o resultado de filbuf no buffer */
+    }
+    m = (n <= z->n) ? n : z->n;  /* minimo de n e z->n */
+    memcpy(b, z->p, m);
+    z->n -= m;
+    z->p += m;
+    b = (char *)b + m;
+    n -= m;
+  }
+  return 0;
+}
diff --git a/zio.h b/zio.h
new file mode 100644
index 00000000..7f25b0ad
--- /dev/null
+++ b/zio.h
@@ -0,0 +1,47 @@
+/*
+* zio.h
+* a generic input stream interface
+* $Id: zio.h,v 1.4 1997/06/13 13:49:16 lhf Exp $
+*/
+
+#ifndef zio_h
+#define zio_h
+
+#include <stdio.h>
+
+#define EOZ	(-1)			/* end of stream */
+
+typedef struct zio ZIO;
+
+int zgetc(ZIO* z);			/* get next byte */
+int zungetc(ZIO* z);			/* put back last byte read */
+int zread(ZIO* z, void* b, int n);	/* read next n bytes */
+int zclose(ZIO* z);			/* close stream */
+
+ZIO* zFopen(ZIO* z, FILE* f);		/* open FILEs */
+ZIO* zfopen(ZIO* z, char* s, char* m);	/* file by name */
+ZIO* zpopen(ZIO* z, char* s, char* m);	/* pipe */
+ZIO* zsopen(ZIO* z, char* s);		/* string */
+ZIO* zmopen(ZIO* z, char* b, int size);	/* memory */
+
+#define zgetc(z)	(--(z)->n>=0 ? ((int)*(z)->p++): (z)->filbuf(z))
+#define zungetc(z)	(++(z)->n,--(z)->p)
+#define zclose(z)	(*(z)->close)(z)
+
+
+
+/* --------- Private Part ------------------ */
+
+#define ZBSIZE	256			/* buffer size */
+
+struct zio {
+ int n;					/* bytes still unread */
+ unsigned char* p;			/* current position in buffer */
+ int (*filbuf)(ZIO* z);
+ int (*close)(ZIO* z);
+ void* u;				/* additional data */
+ unsigned char buffer[ZBSIZE];		/* buffer */
+};
+
+
+#endif