WebSVN – SvarDOS – Diff – /svarcom/trunk/redir.c

 /* This file is part of the SvarCOM project and is published under the terms
  * of the MIT license.
+ *
  * Copyright (C) 2021 Mateusz Viste
+ *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
  * to deal in the Software without restriction, including without limitation
  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  * and/or sell copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, subject to the following conditions:
+ *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
+ *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  * DEALINGS IN THE SOFTWARE.
  */
 #include <string.h> /* memset() */
+#include "env.h"
 #include "helpers.h"
 #include "rmodinit.h"
 #include "redir.h"
 static unsigned short oldstdout = 0xffff;
+/* compute a filename to be used for pipes */
+static unsigned short gentmpfile(char *s) {
+  unsigned short err = 0;
+  /* do I have a %temp% path? */
+  /* TODO */
+  /* if fails, then use truename(\) */
+  if (file_truename(".\\", s) != 0) *s = 0;
+  /* create file */
+  _asm {
+    mov ah, 0x5a
+    mov dx, s
+    xor cx, cx /* file attributes */
+    int 0x21
+    jnc CLOSEFILE
+    mov err, ax
+    jmp DONE
+    /* close file handle */
+    CLOSEFILE:
+    mov ah, 0x3e
+    mov bx, ax
+    int 0x21
+    DONE:
+  }
+  return(err);
+}
+#include <stdio.h>
 /* parse commandline and performs necessary redirections. cmdline is
- * modified so all redirections are cut out. */
+ * modified so all redirections are cut out.
+ * piped commands are move to awaitingcmd for later execution
+ * returns 0 on success, DOS err on failure */
-void redir_parsecmd(struct redir_data *d, char *cmdline) {
+unsigned short redir_parsecmd(struct redir_data *d, char *cmdline, char far *awaitingcmd) {
   unsigned short i;
   unsigned short pipescount = 0;
-  /* NOTE:
+  /* NOTES:
+   *
    * 1. while it is possible to type a command with multiple
    *    redirections, MSDOS executes only the last redirection.
+   *
    * 2. the order in which >, < and | are provided on the command line does
    *    not seem to matter for MSDOS. piped commands are executed first (in
    *    the order they appear) and the result of the last one is redirected to
    *    whenever the last > points at.
+   *    stdin redirection (<) is (obviously) applied to the first command only
    */
   /* preset oldstdout to 0xffff in case no redirection is required */
   oldstdout = 0xffff;
   /* clear out the redir_data struct */
   memset(d, 0, sizeof(*d));
+  *awaitingcmd = 0;
   /* parse the command line and fill struct with pointers */
   for (i = 0;; i++) {
     if (cmdline[i] == '>') {
       cmdline[i] = 0;
       if (cmdline[i + 1] == '>') {
         i++;
         d->stdout_openflag = 0x11;  /* used during int 21h,AH=6C */
       } else {
         d->stdout_openflag = 0x12;
+      }
       d->stdoutfile = cmdline + i + 1;
       while (d->stdoutfile[0] == ' ') d->stdoutfile++;
     } else if (cmdline[i] == '<') {
       cmdline[i] = 0;
       d->stdinfile = cmdline + i + 1;
       while (d->stdinfile[0] == ' ') d->stdinfile++;
     } else if (cmdline[i] == '|') {
       cmdline[i] = 0;
       if (pipescount < REDIR_MAX_PIPES) {
         d->pipes[pipescount++] = cmdline + i + 1;
         while (d->pipes[pipescount][0] == ' ') d->pipes[pipescount]++;
+      }
     } else if (cmdline[i] == 0) {
       break;
+    }
+  }
+  /* if pipes present, write them to awaitingcmd (and stdout redirection too) */
+  if (pipescount != 0) {
+    static char tmpfile[130];
+    for (i = 0; i < pipescount; i++) {
+      if (i != 0) _fstrcat(awaitingcmd, "|");
+      _fstrcat(awaitingcmd, d->pipes[i]);
+    }
+    /* append stdout redirection so I don't forget about it for the last command of the pipe queue */
+    if (d->stdoutfile != NULL) {
+      if (d->stdout_openflag == 0x11) {
+        _fstrcat(awaitingcmd, ">>");
+      } else {
+        _fstrcat(awaitingcmd, ">");
+      }
+      d->stdoutfile = NULL;
+    }
+    /* redirect stdin of next command from a temp file (that is used as my output) */
+    _fstrcat(awaitingcmd, "<");
+    i = gentmpfile(tmpfile);
+    if (i != 0) return(i);
+    _fstrcat(awaitingcmd, tmpfile);
+    /* same file is used as my stdout */
+    d->stdoutfile = tmpfile;
+    d->stdout_openflag = 0x12;
+    /* TODO I need to remember that the tmp file must be removed... */
+/*    outputnl("awaitingcmd:");
+    for (i = 0; awaitingcmd[i] != 0; i++) printf("%c", awaitingcmd[i]);
+    printf("\r\n");*/
+  }
+  return(0);
+}
-/* apply stdin/stdout redirections defined in redir_data, returns 0 on success */
+/* apply stdout redirections defined in redir_data, returns 0 on success */
 int redir_apply(const struct redir_data *d) {
-  if (d->stdinfile != NULL) {
-    outputnl("ERROR: stdin redirection is not supported yet");
-    return(-1);
-  }
   if (d->stdoutfile != NULL) {
     unsigned short openflag = d->stdout_openflag;
     unsigned short errcode = 0;
     unsigned short handle = 0;
     const char *myptr = d->stdoutfile;
     /* */
     _asm {
       push ax
       push bx
       push cx
       push dx
       push si
       mov ax, 0x6c00     /* Extended Open/Create */
       mov bx, 1          /* access mode (0=read, 1=write, 2=r+w */
       xor cx, cx         /* attributes when(if) creating the file (0=normal) */
       mov dx, [openflag] /* action if file exists (0x11=open, 0x12=truncate)*/
       mov si, myptr      /* ASCIIZ filename */
       int 0x21           /* AX=handle on success (CF clear), otherwise dos err */
       mov handle, ax     /* save the file handler */
       jnc JMPEOF
       mov errcode, ax
       jmp DONE
       JMPEOF:
       cmp openflag, word ptr 0x11
       jne DUPSTDOUT
       /* jump to the end of the file (required for >> redirections) */
       mov ax, 0x4202     /* jump to position EOF - CX:DX in handle BX */
       mov bx, handle
       xor cx, cx
       xor dx, dx
       int 0x21
       /* save (duplicate) current stdout so I can revert it later */
       DUPSTDOUT:
       mov ah, 0x45       /* duplicate file handle */
       mov bx, 1          /* handle to dup (1=stdout) */
       int 0x21           /* ax = new file handle */
       mov oldstdout, ax
       /* redirect the stdout handle */
       mov bx, handle     /* dst handle */
       mov cx, 1          /* src handle (1=stdout) */
       mov ah, 0x46       /* redirect a handle */
       int 0x21
       /* close the original file handle (no longer needed) */
       mov ah, 0x3e       /* close a file handle (handle in BX) */
       int 0x21
       DONE:
       pop si
       pop dx
       pop cx
       pop bx
       pop ax
+    }
     if (errcode != 0) {
       nls_outputnl_doserr(errcode);
       return(-1);
+    }
+  }
   return(0);
+}
-/* restores previous stdout/stdin handlers if they have been redirected */
+/* restores previous stdout handle if is has been redirected */
 void redir_revert(void) {
   _asm {
     /* if oldstdout is 0xffff then not redirected */
     cmp word ptr [oldstdout], 0xffff
     je DONE
     /* redirect the stdout handle */
     mov bx, [oldstdout] /* dst handle */
     mov cx, 1           /* src handle (1=stdout) */
     mov ah, 0x46        /* redirect a handle */
     int 0x21
     /* close old handle (in bx already) */
     mov ah, 0x3e
     int 0x21
     mov [oldstdout], 0xffff
     DONE:
+  }
+}

Subversion Repositories SvarDOS

(root)/svarcom/trunk/redir.c – Rev 538 → 543