请教一个脚本问题？

sprayvoice

－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－
#!/bin/sh
if cp "$1" "#$1"
then
vi "$1"
else
echo "Failed to create backup copy"
fi
－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－
请教：
这个脚本中 if cp "$1" "#$1"
"$1" 和 "#$1" 代表什么？

KornLee

$1是第一个位置参数,如:
urscript A
A即为第一个位置参数$1.
#$1,看你的脚本,是生成了一个A文件的备份文件"#A"

sprayvoice

对了，多谢。

sprayvoice

awk '{print ; if (NF != 0) print ""}' infile > outfile

在这行中，print; 代表输出什么？
if (NF!=0)是否指不是空行的行？
print"" 指的又是输出什么？


这些是从这里copy过来的。

For example, suppose I want to turn a document with single-spacing into a document with double-spacing. I could easily do that with the following Awk program:

   awk '{print ; print ""}' infile > outfile

Notice how single-quotes (' ') are used to allow using double-quotes (" ") within the Awk expression. This "hides" special characters from the shell you are using. You could also do this as follows:

   awk "{print ; print \"\"}" infile > outfile

-- but the single-quote method is simpler.

This program does what it supposed to, but it also doubles every blank line in the input file, which leaves a lot of empty space in the output. That's easy to fix, just tell Awk to print an extra blank line if the current line is not blank:

   awk '{print ; if (NF != 0) print ""}' infile > outfile

Glue

第一个print; 等于 print $0; 打出当前行的内容
NF是当前行的记录数，print ""; 是打一个空行。

所以这个脚本是在不是空行的行后加一个空行，
我说的对吧

sprayvoice

明白了。