将输入管道输入脚本 [英] Pipe input into a script

问题描述

我用ksh编写了一个shell脚本，将CSV文件转换为Spreadsheet XML文件.它获取一个现有的CSV文件(脚本中变量的路径)，然后创建一个新的输出文件.xls.该脚本没有位置参数. CSV的文件名当前已硬编码到脚本中.

I have written a shell script in ksh to convert a CSV file into Spreadsheet XML file. It takes an existing CSV file (the path to which is a variable in the script), and then creates a new output file .xls. The script has no positional parameters. The file name of the CSV is currently hardcoded into the script.

我想修改脚本，以便它可以从管道中获取输入CSV数据，以便也可以通过管道将.xls输出数据或通过管道重定向(>)到命令行上的文件.

I would like to amend the script so it can take the input CSV data from a pipe, and so that the .xls output data can also be piped or redirected (>) to a file on the command line.

这是如何实现的?

我正在努力寻找有关如何编写Shell脚本以从管道获取输入的文档.看来，"read"仅用于kb中的std输入.

I am struggling to find documentation on how to write a shell script to take input from a pipe. It appears that 'read' is only used for std input from kb.

谢谢.

以下脚本以获取信息(根据问题的答案，现在已修改为通过猫从管道中获取输入.

Edit : script below for info (now amended to take input from a pipe via the cat, as per the answer to the question.

#!/bin/ksh
#Script to convert a .csv data to "Spreadsheet ML" XML format - the XML scheme for Excel 2003
#
#   Take CSV data as standard input
#   Out XLS data as standard output
#

DATE=`date +%Y%m%d`

#define tmp files
INPUT=tmp.csv
IN_FILE=in_file.csv

#take standard input and save as $INPUT (tmp.csv)
cat > $INPUT

#clean input data and save as $IN_FILE (in_file.csv)
grep '.' $INPUT | sed 's/ *,/,/g' | sed 's/, */,/g' > $IN_FILE

#delete original $INPUT file (tmp.csv)
rm $INPUT

#detect the number of columns and rows in the input file
ROWS=`wc -l < $IN_FILE | sed 's/ //g' `
COLS=`awk -F',' '{print NF; exit}' $IN_FILE`
#echo "Total columns is $COLS"
#echo "Total rows  is $ROWS"

#create start of Excel File
echo "<?xml version=\"1.0\"?>
<?mso-application progid=\"Excel.Sheet\"?> 
<Workbook xmlns=\"urn:schemas-microsoft-com:office:spreadsheet\"
        xmlns:o=\"urn:schemas-microsoft-com:office:office\"
        xmlns:x=\"urn:schemas-microsoft-com:office:excel\"
        xmlns:ss=\"urn:schemas-microsoft-com:office:spreadsheet\"
        xmlns:html=\"http://www.w3.org/TR/REC-html40\">
<DocumentProperties xmlns=\"urn:schemas-microsoft-com:office:office\">
      <Author>Ben Hamilton</Author>
      <LastAuthor>Ben Hamilton</LastAuthor>
      <Created>${DATE}</Created>
      <Company>MCC</Company>
      <Version>10.2625</Version>
</DocumentProperties>
<ExcelWorkbook xmlns=\"urn:schemas-microsoft-com:office:excel\">
        <WindowHeight>6135</WindowHeight>
        <WindowWidth>8445</WindowWidth>
        <WindowTopX>240</WindowTopX>
        <WindowTopY>120</WindowTopY>
        <ProtectStructure>False</ProtectStructure>
        <ProtectWindows>False</ProtectWindows>
</ExcelWorkbook>

<Styles>
      <Style ss:ID=\"Default\" ss:Name=\"Normal\">
            <Alignment ss:Vertical=\"Bottom\" />
            <Borders />
            <Font />
            <Interior />
            <NumberFormat />
            <Protection />
      </Style>
      <Style ss:ID=\"AcadDate\">
      <NumberFormat ss:Format=\"Short Date\"/>    
      </Style> 
</Styles>
<Worksheet ss:Name=\"Sheet 1\">
<Table>
<Column ss:AutoFitWidth=\"1\" />"

#for each row in turn, create the XML elements for row/column
r=1
while (( r <= $ROWS ))
do
   echo "<Row>\n" 
    c=1
    while (( c <= $COLS ))
    do
        DATA=`sed -n "${r}p" $IN_FILE | cut -d "," -f $c `

        if [[ "${DATA}" == [0-9][0-9]\.[0-9][0-9]\.[0-9][0-9][0-9][0-9] ]]; then

            DD=`echo $DATA | cut -d "." -f 1`
            MM=`echo $DATA | cut -d "." -f 2`
            YYYY=`echo $DATA | cut -d "." -f 3`     
            echo "<Cell ss:StyleID=\"AcadDate\"><Data ss:Type=\"DateTime\">${YYYY}-${MM}-${DD}T00:00:00.000</Data></Cell>"
        else        
            echo "<Cell><Data ss:Type=\"String\">${DATA}</Data></Cell>" 
        fi
        (( c+=1 ))
    done
    echo "</Row>"
   (( r+=1 ))
done

echo "</Table>\n</Worksheet>\n</Workbook>"


rm $IN_FILE > /dev/null

exit 0

推荐答案

命令从启动它们的进程中继承其标准输入.在您的情况下，您的脚本会为其运行的每个命令提供其标准输入.一个简单的示例脚本:

Commands inherit their standard input from the process that starts them. In your case, your script provides its standard input for each command that it runs. A simple example script:

#!/bin/bash
cat > foo.txt

将数据插入到您的Shell脚本中会导致cat读取该数据，因为cat会从您的脚本继承其标准输入.

Piping data into your shell script causes cat to read that data, since cat inherits its standard input from your script.

$ echo "Hello world" | myscript.sh
$ cat foo.txt
Hello world

如果您没有其他命令来读取或处理脚本的标准输入，则Shell提供read命令以将文本从标准输入读取到shell变量中.

The read command is provided by the shell for reading text from standard input into a shell variable if you don't have another command to read or process your script's standard input.

#!/bin/bash

read foo
echo "You entered '$foo'"

$ echo bob | myscript.sh
You entered 'bob'

这篇关于将输入管道输入脚本的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！