making a bash script

student04 · 01-10-2005, 11:47 AM

Here's my situation:

I want to run a script that creates html pages from my man pages. I already have the tool to do that, and know a little bit about scripting, but not that much. I've read through some tutorials already, and it's difficult to find what i'm looking for.

So far I list the contents of three folders and concatenate them into one file, thus giving me one long list of single words (commands, in this case):

Code:

#!/bin/bash
path1=/bin
path2=/usr/bin
path3=/usr/local/bin

filename=allBinaries.txt

ls -1 ${path1} > ${filename}
ls -1 ${path2} >> ${filename}
ls -1 ${path3} >> ${filename}

I would like to read in each line from ${filename} and store each string (each line - each command) into one spot in an array. I can't seem to figure out how to list one line of a file with more, less, tail or cat (but i may have overlooked it). Is this even possible? Or even better, would i be able to pipe the output of ls -l into an array?

Thanks for any feedback.

bigrigdriver · 01-10-2005, 01:20 PM

Download a copy of the "Absolute bash-scripting guide'. Ch. 26 covers arrays, with several examples.
It should be fairly straightforward to declare an array, and use a for-next loop to read from a text file, line-by-line, into an array.

homey · 01-10-2005, 01:36 PM

Maybe something like this will get you started

Code:

#!/bin/bash
path="/bin /usr/bin /usr/local/bin"

echo > /home/filename.txt

#save the list
for i in `ls -1 $path` ;do
echo $i >> /home/filename.txt
done

#do something else
file=/home/filename.txt
cat ${file} |\
while read name; do
echo $name
done

student04 · 01-10-2005, 07:13 PM

Thanks both of you

student04 · 01-10-2005, 11:41 PM

Though i do have one more question...

Code:

...
# create html files from man pages
line=1
while [ ${line} -le ${number} ]
do  
  if [ -f `man -w ${array[${line}]}` ]
      then
      echo "Creating html" ${array[${line}]}".html"
      ${man} ${array[${line}]} | ${man2html} > ${array[${line}]}".html"
      line=${line}+1
  else
      echo "============================"
      line=${line}+1
  fi
done

When that checks for a man page of "bash2" (which doesn't exist) it still executes as TRUE and makes a man2html html page, but with nothing in it. Why is this not working?

How could I make the if statement return FALSE when a man page does not exist?

Thanks

bigrigdriver · 01-11-2005, 03:41 AM

Here is a snippet of code I used in a Unix class a couple of years ago. In the script from which this is excerpted, the user supplies two filenames, and this code checks to see if the file exists and whether it's a regular file or a directory.
You could write a bash function to enclude code to test for the existance of a file before writing the html code.

Code:

# check for valid filename entries in this directory  
if [ -e "$1" -a -e "$2" -a -r "$1" -a -d "$2" ]; then
    echo "$1 is a regular file; $2 is a directory."
    echo "Exiting"
    exit 40 
elif [ -e "$1" -a -e "$2" -a -d "$1" -a -r "$2" ]; then
    echo "$1 is a directory; $2 is a regular file."
    echo "Exiting"
    exit 40 
elif [ -e "$1" -a -e "$2" -a ! -d "$1" -a ! -r "$1" -a \
    ! -d "$2" -a ! -r "$2" ]; then
    echo "Neither file is a directory or regular file."
    echo "Exiting"
    exit 30 
elif [ ! -e "$1" -a ! -e "$2" ]; then
    echo "Neither file exists in this directory."
    echo "Exiting"
    exit 30 
elif  [ ! -e "$1" -o ! -e "$2" ]; then
    echo "One of the files doesn't exist in this directory." 
    echo "Exiting"
    exit 30 
else [ -e "$1" -a -e "$2" -a -r "$1" -a -r "$2" ]
    echo "Both files exist in this directory."
    echo "Both files are regular files." 
fi

In bash scripting,
-e = exists
! -e = does not exist
-r = regular file
! -r = nor a regular file
-d = directory
! -d = not a directory
-a = and
-o = or