workbench/c/Shell/convertBackTicks.c

   1 /*
   2     Copyright (C) 1995-2011, The AROS Development Team. All rights reserved.
   3     $Id$
   4  */
   5
   6 #include <proto/dos.h>
   7
   8 #include <stdio.h>
   9
  10 #include "buffer.h"
  11 #include "Shell.h"
  12
  13 #include <aros/debug.h>
  14
  15 // TODO:  remove these comments when fixed and validated
  16 // TODO:  C++ style comments should be avoided
  17 // FIXME: why use a $ in a filename ? just to try the resistance of bad FS
  18 // TODO:  use pipes instead of plain file ?
  19
  20 #define SHELL_EMBED "T:Shell$embed"
  21
  22 /* BackTicks handling... like V45, we allow several embedded
  23  * commands, while V40 only allows one per line.
  24  */
  25 LONG convertBackTicks(ShellState *ss, Buffer *in, Buffer *out, BOOL *quoted)
  26 {
  27     Buffer embedIn = {0}, embedOut = {0}; /* TODO pre-alloc */
  28     LONG c = 0, error = 0, n = in->len, p = 0;
  29     TEXT buf[512] = SHELL_EMBED;
  30     ShellState ess = {0};
  31
  32     ess.ss_DOSBase = DOSBase;
  33     ess.ss_SysBase = SysBase;
  34
  35     for (++in->cur; in->cur < n; p = c)
  36     {
  37         c = in->buf[in->cur];
  38
  39         if (p == '*')
  40         {
  41             c = 0;
  42             bufferCopy(in, &embedIn, 1, SysBase);
  43         }
  44         else if (c == '`')
  45             break;
  46         else
  47             bufferCopy(in, &embedIn, 1, SysBase);
  48     }
  49
  50     if (c != '`')
  51     {
  52         bufferCopy(&embedIn, out, embedIn.len, SysBase);
  53         goto freebufs;
  54     }
  55
  56     ++in->cur; /* last backtick */
  57
  58     if (embedIn.len <= 0) /* `` empty command, no output */
  59         goto freebufs;
  60
  61     initDefaultInterpreterState(&ess);
  62
  63     /* The Amiga shell has severe problems when using
  64      * redirections in embedded commands so here, the
  65      * semantics differ somewhat. Unix shells seems to be
  66      * a little bit sloppy with this, too.
  67      * If you really wanted to, you could track down
  68      * uses of > and >> and make them work inside ` `, too,
  69      * but this seems to be rather much work for little gain.
  70      */
  71     if ((error = Redirection_init(&ess)))
  72         goto cleanup;
  73
  74     /* Construct temporary output filename */
  75     l2a(ss->cliNumber, buf + sizeof(SHELL_EMBED) - 1);
  76
  77     if (!(ess.newOut = Open(buf, MODE_NEWFILE)))
  78     {
  79         error = IoErr();
  80         goto cleanup;
  81     }
  82
  83     ess.oldOut = SelectOutput(ess.newOut);
  84
  85     /* Embedded command isn't echo'ed, but its result will be integrated
  86        in final command line, which will be echo'ed if the var is set. */
  87     D(bug("[Shell] embedded command: %s\n", embedIn.buf));
  88     if ((error = checkLine(&ess, &embedIn, &embedOut, FALSE)) == 0)
  89     {
  90         LONG i, len = -1, size;
  91
  92         /* copy result to output */
  93         if ((size = Seek(ess.newOut, 0, OFFSET_BEGINNING)) >= 0)
  94         {
  95             while ((len = Read(ess.newOut, buf, 512)) > 0)
  96             {
  97                 for (i = 0; i < len - 1; ++i) /* replace all \n but last */
  98                     if (buf[i] == '\n')
  99                         buf[i] = ' ';
 100
 101                 size -= len;
 102
 103                 if (size <= 0 && buf[i] == '\n')
 104                     --len;
 105
 106                 bufferAppend(buf, len, out, SysBase);
 107             }
 108         }
 109
 110         if (len == -1)
 111             error = IoErr();
 112     }
 113
 114 cleanup:
 115     Redirection_release(&ess);
 116     /* TODO: delete generated file */
 117 freebufs:
 118     bufferFree(&embedIn, SysBase);
 119     bufferFree(&embedOut, SysBase);
 120
 121     D(bug("[Shell] embedded command done, error = %d\n", error));
 122     return error;
 123 }