fix code to read from pipes to request only what it needs

[unix-history] / usr / src / usr.bin / pascal / px / int.c

diff --git a/usr/src/usr.bin/pascal/px/int.c b/usr/src/usr.bin/pascal/px/int.c
index 072e166..28e959b 100644 (file)
--- a/usr/src/usr.bin/pascal/px/int.c
+++ b/usr/src/usr.bin/pascal/px/int.c
@@ -24,11 +24,10 @@ main(ac,av)
 
 {
        register char *objprog, *file;
 
 {
        register char *objprog, *file;

-       register long bytesread, block;
+       register long bytesread, bytestoread, block;

        register FILE *prog;
        struct   pxhdr pxhd;
 #      define   pipe 3
        register FILE *prog;
        struct   pxhdr pxhd;
 #      define   pipe 3

-#      define   pipesize 4096

 
        /*
         * Initialize everything
 
        /*
         * Initialize everything


@@ -40,88 +39,73 @@ main(ac,av)
        /*
         * Determine how PX was invoked, and how to process the program 
         */
        /*
         * Determine how PX was invoked, and how to process the program 
         */

-       if (_argv[0][0] == '-' && _argv[0][1] == 'o')
-               {
+       if (_argv[0][0] == '-' && _argv[0][1] == 'o') {

                file = &_argv[0][2];
                _mode = PIX;
                file = &_argv[0][2];
                _mode = PIX;

-               }
-       else if (_argc <= 1)
-               {
+       } else if (_argc <= 1) {

                file = "obj";
                _mode = PX;
                file = "obj";
                _mode = PX;

-               }
-       else if (_argv[1][0] != '-')
-               {
+       } else if (_argv[1][0] != '-') {

                file = _argv[1];
                _mode = PX;
                file = _argv[1];
                _mode = PX;

-               }
-       else if (_argv[1][1] == 0)
-               {
+       } else if (_argv[1][1] == 0) {

                file = _argv[0];
                _mode = PIPE;
                _argc -= 1;
                _argv[1] = _argv[0];
                _argv = &_argv[1];
                file = _argv[0];
                _mode = PIPE;
                _argc -= 1;
                _argv[1] = _argv[0];
                _argv = &_argv[1];

-               }
-       else
-               {
+       } else {

                fputs("Improper specification of object file to PX\n",stderr);
                exit(1);
                fputs("Improper specification of object file to PX\n",stderr);
                exit(1);

-               }
+       }

 \f
        /*
         * Process program header information
         */
 \f
        /*
         * Process program header information
         */

-       if (_mode == PIPE)
+       if (_mode == PIPE) {

                read(pipe,&pxhd,sizeof(struct pxhdr));
                read(pipe,&pxhd,sizeof(struct pxhdr));

-       else
-               {
+       } else {

                prog = fopen(file,"r");
                prog = fopen(file,"r");

-               if (prog == NULL)
-                       {
+               if (prog == NULL) {

                        perror(file);
                        exit(1);
                        perror(file);
                        exit(1);

-                       }
+               }

                fseek(prog,(long)(HEADER_BYTES-sizeof(struct pxhdr)),0);
                fread(&pxhd,sizeof(struct pxhdr),1,prog);
                fseek(prog,(long)(HEADER_BYTES-sizeof(struct pxhdr)),0);
                fread(&pxhd,sizeof(struct pxhdr),1,prog);

-               }
-       if (pxhd.maketime < createtime)
-               {
+       }
+       if (pxhd.maketime < createtime) {

                fprintf(stderr,"%s is obsolete and must be recompiled\n",file);
                exit(1);
                fprintf(stderr,"%s is obsolete and must be recompiled\n",file);
                exit(1);

-               }
-       if (pxhd.magicnum != MAGICNUM)
-               {
+       }
+       if (pxhd.magicnum != MAGICNUM) {

                fprintf(stderr,"%s is not a Pascal interpreter file\n",file);
                exit(1);
                fprintf(stderr,"%s is not a Pascal interpreter file\n",file);
                exit(1);

-               }
+       }

 \f
        /*
         * Load program into memory
         */
        objprog = malloc((int)pxhd.objsize);
 \f
        /*
         * Load program into memory
         */
        objprog = malloc((int)pxhd.objsize);

-       if (_mode == PIPE)
-               {
+       if (_mode == PIPE) {
+               bytestoread = pxhd.objsize;

                bytesread = 0;
                bytesread = 0;

-               do
-                       {
-                       block = read(pipe,(int)(objprog+bytesread),pipesize);
-                       bytesread += block;
+               do      {
+                       block = read(pipe,(int)(objprog+bytesread),bytestoread);
+                       if (block > 0) {
+                               bytesread += block;
+                               bytestoread -= block;

                        }
                        }

-                       while (block);
-               }
-       else
-               {
+               } while (block > 0);
+       } else {

                bytesread = fread(objprog,1,(int)pxhd.objsize,prog);
                fclose(prog);
                if (_mode == PIX)
                        unlink(file);
                bytesread = fread(objprog,1,(int)pxhd.objsize,prog);
                fclose(prog);
                if (_mode == PIX)
                        unlink(file);

-               }
-       if (bytesread != pxhd.objsize)
-               {
+       }
+       if (bytesread != pxhd.objsize) {

                fprintf(stderr,"Read error occurred while loading %s\n",file);
                exit(1);
                fprintf(stderr,"Read error occurred while loading %s\n",file);
                exit(1);

-               }
+       }

        if (_mode == PIX)
                fputs("Execution begins...\n",stderr);
        /*
        if (_mode == PIX)
                fputs("Execution begins...\n",stderr);
        /*