dosbatch.html

Shall高级编程

></TABLE
><HR></DIV
><P
><A
NAME="DOSUNIXEQUIV"
></A
></P
><P
>Batch files usually contain DOS commands. These must be
	translated into their UNIX equivalents in order to convert a
	batch file into a shell script.</P
><DIV
CLASS="TABLE"
><HR><A
NAME="AEN22241"
></A
><P
><B
>Table L-2. DOS commands and their UNIX equivalents</B
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><THEAD
><TR
><TH
ALIGN="LEFT"
VALIGN="TOP"
>DOS Command</TH
><TH
ALIGN="LEFT"
VALIGN="TOP"
>UNIX Equivalent</TH
><TH
ALIGN="LEFT"
VALIGN="TOP"
>Effect</TH
></TR
></THEAD
><TBODY
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>ASSIGN</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>ln</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>link file or directory</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>ATTRIB</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>chmod</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>change file permissions</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>CD</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>cd</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>change directory</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>CHDIR</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>cd</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>change directory</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>CLS</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>clear</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>clear screen</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>COMP</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>diff, comm, cmp</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>file compare</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>COPY</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>cp</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>file copy</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>Ctl-C</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Ctl-C</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>break (signal)</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>Ctl-Z</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Ctl-D</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>EOF (end-of-file)</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>DEL</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>rm</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>delete file(s)</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>DELTREE</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>rm -rf</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>delete directory recursively</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>DIR</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>ls -l</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>directory listing</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>ERASE</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>rm</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>delete file(s)</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>EXIT</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>exit</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>exit current process</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>FC</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>comm, cmp</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>file compare</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>FIND</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>grep</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>find strings in files</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>MD</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>mkdir</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>make directory</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>MKDIR</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>mkdir</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>make directory</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>MORE</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>more</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>text file paging filter</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>MOVE</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>mv</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>move</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>PATH</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>$PATH</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>path to executables</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>REN</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>mv</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>rename (move)</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>RENAME</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>mv</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>rename (move)</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>RD</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>rmdir</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>remove directory</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>RMDIR</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>rmdir</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>remove directory</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>SORT</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>sort</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>sort file</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>TIME</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>date</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>display system time</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>TYPE</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>cat</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>output file to <TT
CLASS="FILENAME"
>stdout</TT
></TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>XCOPY</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>cp</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>(extended) file copy</TD
></TR
></TBODY
></TABLE
><HR></DIV
><DIV
CLASS="NOTE"
><TABLE
CLASS="NOTE"
WIDTH="100%"
BORDER="0"
><TR
><TD
WIDTH="25"
ALIGN="CENTER"
VALIGN="TOP"
><IMG
SRC="common/note.png"
HSPACE="5"
ALT="Note"></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
><P
>Virtually all UNIX and shell operators and commands have
	many more options and enhancements than their DOS and batch file
	counterparts. Many DOS batch files rely on auxiliary utilities,
	such as <B
CLASS="COMMAND"
>ask.com</B
>, a crippled counterpart to
	<A
HREF="internal.html#READREF"
>read</A
>.</P
><P
>DOS supports only a very limited and incompatible subset of
	filename <A
HREF="globbingref.html"
>wild-card expansion</A
>,
	recognizing just the <SPAN
CLASS="TOKEN"
>*</SPAN
> and <SPAN
CLASS="TOKEN"
>?</SPAN
>
	characters.</P
></TD
></TR
></TABLE
></DIV
><P
>Converting a DOS batch file into a shell script is generally
	straightforward, and the result ofttimes reads better than the
	original.</P
><DIV
CLASS="EXAMPLE"
><HR><A
NAME="VIEWDAT"
></A
><P
><B
>Example L-1. VIEWDATA.BAT: DOS Batch File</B
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>   1&nbsp;REM VIEWDATA
   2&nbsp;
   3&nbsp;REM INSPIRED BY AN EXAMPLE IN "DOS POWERTOOLS"
   4&nbsp;REM                           BY PAUL SOMERSON
   5&nbsp;
   6&nbsp;
   7&nbsp;@ECHO OFF
   8&nbsp;
   9&nbsp;IF !%1==! GOTO VIEWDATA
  10&nbsp;REM  IF NO COMMAND-LINE ARG...
  11&nbsp;FIND "%1" C:\BOZO\BOOKLIST.TXT
  12&nbsp;GOTO EXIT0
  13&nbsp;REM  PRINT LINE WITH STRING MATCH, THEN EXIT.
  14&nbsp;
  15&nbsp;:VIEWDATA
  16&nbsp;TYPE C:\BOZO\BOOKLIST.TXT | MORE
  17&nbsp;REM  SHOW ENTIRE FILE, 1 PAGE AT A TIME.
  18&nbsp;
  19&nbsp;:EXIT0</PRE
></TD
></TR
></TABLE
><HR></DIV
><P
>      The script conversion is somewhat of an improvement.
	<A
NAME="AEN22409"
HREF="#FTN.AEN22409"
>[1]</A
>
      </P
><DIV
CLASS="EXAMPLE"
><HR><A
NAME="VIEWDATA"
></A
><P
><B
>Example L-2. <I
CLASS="FIRSTTERM"
>viewdata.sh</I
>: Shell Script Conversion
	of VIEWDATA.BAT</B
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>   1&nbsp;#!/bin/bash
   2&nbsp;# viewdata.sh
   3&nbsp;# Conversion of VIEWDATA.BAT to shell script.
   4&nbsp;
   5&nbsp;DATAFILE=/home/bozo/datafiles/book-collection.data
   6&nbsp;ARGNO=1
   7&nbsp;
   8&nbsp;# @ECHO OFF                 Command unnecessary here.
   9&nbsp;
  10&nbsp;if [ $# -lt "$ARGNO" ]    # IF !%1==! GOTO VIEWDATA
  11&nbsp;then
  12&nbsp;  less $DATAFILE          # TYPE C:\MYDIR\BOOKLIST.TXT | MORE
  13&nbsp;else
  14&nbsp;  grep "$1" $DATAFILE     # FIND "%1" C:\MYDIR\BOOKLIST.TXT
  15&nbsp;fi  
  16&nbsp;
  17&nbsp;exit 0                    # :EXIT0
  18&nbsp;
  19&nbsp;#  GOTOs, labels, smoke-and-mirrors, and flimflam unnecessary.
  20&nbsp;#  The converted script is short, sweet, and clean,
  21&nbsp;#+ which is more than can be said for the original.</PRE
></TD
></TR
></TABLE
><HR></DIV
><P
>Ted Davis' <A
HREF="http://www.maem.umr.edu/batch/"
TARGET="_top"
>Shell
	Scripts on the PC</A
> site has a set of comprehensive
	tutorials on the old-fashioned art of batch file
	programming. Certain of his ingenious techniques could conceivably
	have relevance for shell scripts.</P
></DIV
><H3
CLASS="FOOTNOTES"
>Notes</H3
><TABLE
BORDER="0"
CLASS="FOOTNOTES"
WIDTH="100%"
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="5%"
><A
NAME="FTN.AEN22409"
HREF="dosbatch.html#AEN22409"
>[1]</A
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="95%"
><P
>Various readers have suggested modifications
	of the above batch file to prettify it and make it more
	compact and efficient. In the opinion of the <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>ABS
	Guide</I
></SPAN
> author, this is wasted effort. A Bash script
	can access a DOS filesystem, or even an NTFS partition (with
	the help of <A
HREF="http://www.ntfs-3g.org"
TARGET="_top"
>ntfs-3g</A
>)
	to do batch or scripted operations.</P
></TD
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