Sponsored Content
Full Discussion: Bash while loop problem
Top Forums Shell Programming and Scripting Bash while loop problem Post 302128095 by xtos on Sunday 22nd of July 2007 03:02:00 AM
Old 07-22-2007
i am a beginner in unix, and occasionally i name my scripts after a command name...i have spent hours trying to figure what is wrong before i realized its i have named that script after a command name.
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Simple bash for loop problem

I'm just trying to make a script that runs in command line to echo each line in a text file. Everything i found on google is telling me to do it like this but when I run it it just echos removethese.txt and thats it. Anyone know what im doing wrong? for i in removethese.txt; do echo $i; done ... (4 Replies)
Discussion started by: kingdbag
4 Replies

2. Shell Programming and Scripting

bash and ksh: variable lost in loop in bash?

Hi, I use AIX (ksh) and Linux (bash) servers. I'm trying to do scripts to will run in both ksh and bash, and most of the time it works. But this time I don't get it in bash (I'm more familar in ksh). The goal of my script if to read a "config file" (like "ini" file), and make various report.... (2 Replies)
Discussion started by: estienne
2 Replies

3. Shell Programming and Scripting

problem with while loop in BASH shell

I have file named script1 as follows: #!/bin/bash count="0" echo "hello" echo "$count" while do echo "$count" count=`expr $count + 1` done ----------- when I run it, I get ./script1: line 9: syntax error near unexpected token `done' ./script1: line 9: `done' I... (6 Replies)
Discussion started by: npatwardhan
6 Replies

4. Shell Programming and Scripting

bash & Ksh loop problem

hi i was trying to optimize one script and i came across this problem .. i am putting some pseudo code here $ >cat a.sh ls | while read I do i=$(($i + 1)) done echo "total no of files : " $ >ksh a.sh total no of files : $ >bash a.sh total no of files : why is... (1 Reply)
Discussion started by: zedex
1 Replies

5. Shell Programming and Scripting

Using variables created sequentially in a loop while still inside of the loop [bash]

I'm trying to understand if it's possible to create a set of variables that are numbered based on another variable (using eval) in a loop, and then call on it before the loop ends. As an example I've written a script called question (The fist command is to show what is the contents of the... (2 Replies)
Discussion started by: DeCoTwc
2 Replies

6. Shell Programming and Scripting

Problem with for loop in bash

I'm trying to do a script where I want to see if all users home directories are only writable by owner. However, in my script I do not know how to implement the for loop so that all directories are checked. In mine, I am only checking the permissions for the first directory found. I do know that a... (3 Replies)
Discussion started by: detatchedd
3 Replies

7. Shell Programming and Scripting

BASH loop inside a loop question

Hi all Sorry for the basic question, but i am writing a shell script to get around a slightly flaky binary that ships with one of our servers. This particular utility randomly generates the correct information and could work first time or may work on the 12th or 100th attempt etc !.... (4 Replies)
Discussion started by: rethink
4 Replies

8. Shell Programming and Scripting

problem access array outside of loop in bash

Below is a test script I was trying to use so that I could understand why the logic was not working in a larger script. While accessing and printing array data inside the while loop, everything is fine. Outside the loop, i guess everything is null?? The for loop that is meant to cycle... (4 Replies)
Discussion started by: adlmostwanted
4 Replies

9. Shell Programming and Scripting

If loop in bash

Hello, I have a script that runs a series of commands. Halfway through the script, I want it to check whether everything is going alright: if it is, to proceed with the script, if it isn't to repeat the last step until it gets it right. My code so far looks like this, simplified a bit: ... (3 Replies)
Discussion started by: Leo_Boon
3 Replies

10. UNIX for Dummies Questions & Answers

Problem with multiple grep in bash loop

Hello, I am trying to create a matrix of 0's and 1's depending on whether a gene and sample name are found in the same line in a file called results.txt. An example of the results.txt file is (tab-delimited): Sample1 Gene1 ## Gene2 ## Sample2 Gene2 ## Gene 4 ## Sample3 Gene3 ... (2 Replies)
Discussion started by: InfoSeeker2
2 Replies
AUTOEXPECT(1)						      General Commands Manual						     AUTOEXPECT(1)

NAME
autoexpect - generate an Expect script from watching a session SYNOPSIS
autoexpect [ args ] [ program args... ] INTRODUCTION
autoexpect watches you interacting with another program and creates an Expect script that reproduces your interactions. For straightline scripts, autoexpect saves substantial time over writing scripts by hand. Even if you are an Expect expert, you will find it convenient to use autoexpect to automate the more mindless parts of interactions. It is much easier to cut/paste hunks of autoexpect scripts together than to write them from scratch. And if you are a beginner, you may be able to get away with learning nothing more about Expect than how to call autoexpect. The simplest way to use autoexpect is to call it from the command line with no arguments. For example: % autoexpect By default, autoexpect spawns a shell for you. Given a program name and arguments, autoexpect spawns that program. For example: % autoexpect ftp ftp.cme.nist.gov Once your spawned program is running, interact normally. When you have exited the shell (or program that you specified), autoexpect will create a new script for you. By default, autoexpect writes the new script to "script.exp". You can override this with the -f flag fol- lowed by a new script name. The following example runs "ftp ftp.cme.nist.gov" and stores the resulting Expect script in the file "nist". % autoexpect -f nist ftp ftp.cme.nist.gov It is important to understand that autoexpect does not guarantee a working script because it necessarily has to guess about certain things - and occasionally it guesses wrong. However, it is usually very easy to identify and fix these problems. The typical problems are: o Timing. A surprisingly large number of programs (rn, ksh, zsh, telnet, etc.) and devices (e.g., modems) ignore keystrokes that arrive "too quickly" after prompts. If you find your new script hanging up at one spot, try adding a short sleep just before the previous send. You can force this behavior throughout by overriding the variable "force_conservative" near the beginning of the generated script. This "conservative" mode makes autoexpect automatically pause briefly (one tenth of a second) before sending each char- acter. This pacifies every program I know of. This conservative mode is useful if you just want to quickly reassure yourself that the problem is a timing one (or if you really don't care about how fast the script runs). This same mode can be forced before script generation by using the -c flag. Fortunately, these timing spots are rare. For example, telnet ignores characters only after entering its escape sequence. Modems only ignore characters immediately after connecting to them for the first time. A few programs exhibit this behavior all the time but typically have a switch to disable it. For example, rn's -T flag disables this behavior. The following example starts autoexpect in conservative mode. autoexpect -c The -C flag defines a key to toggle conservative mode. The following example starts autoexpect (in non-conservative mode) with ^L as the toggle. (Note that the ^L is entered literally - i.e., enter a real control-L). autoexpect -C ^L The following example starts autoexpect in conservative mode with ^L as the toggle. autoexpect -c -C ^L o Echoing. Many program echo characters. For example, if you type "more" to a shell, what autoexpect actually sees is: you typed 'm', computer typed 'm', you typed 'o', computer typed 'o', you typed 'r', computer typed 'r', ... Without specific knowledge of the program, it is impossible to know if you are waiting to see each character echoed before typ- ing the next. If autoexpect sees characters being echoed, it assumes that it can send them all as a group rather than inter- leaving them the way they originally appeared. This makes the script more pleasant to read. However, it could conceivably be incorrect if you really had to wait to see each character echoed. o Change. Autoexpect records every character from the interaction in the script. This is desirable because it gives you the ability to make judgements about what is important and what can be replaced with a pattern match. On the other hand, if you use commands whose output differs from run to run, the generated scripts are not going to be correct. For example, the "date" command always produces different output. So using the date command while running autoexpect is a sure way to produce a script that will require editing in order for it to work. The -p flag puts autoexpect into "prompt mode". In this mode, autoexpect will only look for the the last line of program output - which is usually the prompt. This handles the date problem (see above) and most others. The following example starts autoexpect in prompt mode. autoexpect -p The -P flag defines a key to toggle prompt mode. The following example starts autoexpect (in non-prompt mode) with ^P as the toggle. Note that the ^P is entered literally - i.e., enter a real control-P. autoexpect -P ^P The following example starts autoexpect in prompt mode with ^P as the toggle. autoexpect -p -P ^P OTHER FLAGS
The -quiet flag disables informational messages produced by autoexpect. The -Q flag names a quote character which can be used to enter characters that autoexpect would otherwise consume because they are used as toggles. The following example shows a number of flags with quote used to provide a way of entering the toggles literally. autoexpect -P ^P -C ^L -Q ^Q STYLE
I don't know if there is a "style" for Expect programs but autoexpect should definitely not be held up as any model of style. For example, autoexpect uses features of Expect that are intended specifically for computer-generated scripting. So don't try to faithfully write scripts that appear as if they were generated by autoexpect. This is not useful. On the other hand, autoexpect scripts do show some worthwhile things. For example, you can see how any string must be quoted in order to use it in a Tcl script simply by running the strings through autoexpect. SEE ALSO
"Exploring Expect: A Tcl-Based Toolkit for Automating Interactive Programs" by Don Libes, O'Reilly and Associates, January 1995. AUTHOR
Don Libes, National Institute of Standards and Technology expect and autoexpect are in the public domain. NIST and I would appreciate credit if these programs or parts of them are used. 30 June 1995 AUTOEXPECT(1)
All times are GMT -4. The time now is 09:12 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy