Sponsored Content
Top Forums Shell Programming and Scripting why read line skips some lines... Post 302138786 by bluemoon1 on Wednesday 3rd of October 2007 11:57:47 AM
Old 10-03-2007
why read line skips some lines...

Dear Guru:

This has got to be a difficult question, as I've worked on it for a good amount of time now & still puzzled...

So here is the simplified logic in my code:

while read LINE
do
#install a pkg with the name extracted from this line
install_pkg name
done < fileWithPkgNamesToBeInstalled

Say, I have 30 of such lines in the file, everything is fine except once it's finished a particular pkg install (which completed successfully with no error), it will skip the next 3 lines in the file, in other words, that 3 pkgs will not get installed.

If I commented out the install function then I can see all the lines including the ones previously being skipped (e.g. "echo $LINE" will not print the 3 lines in the above code):

while read LINE
do
#install a pkg with the name extracted from this line
# install_pkg name
echo $LINE
done < file

I moved that particular line in the file associated with the pkg to any where else, then still with 3 lines skipped, but they moved to a different place just to follow immediately that line.

Can anyone explain why??
Your response would be highly appreciated.
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Read lines till a blank line is encountered

Hi, I have reached at a specified offset from the start of file. My requirement is that I want to read only those lines, which have the string READ / ALTER / UPDATE. As soon as, none of these literals are found in the subsequent line, I want to stop reading. Is there any feature of grep which... (1 Reply)
Discussion started by: saurabhsinha23
1 Replies

2. Shell Programming and Scripting

cat file1 read line-per-line then grep -A 15 lines down in fileb

STEP 1 # Set variable FILE=/tmp/mainfile SEARCHFILE =/tmp/searchfile # THIS IS THE MAIN FILE. cat /tmp/mainfile Interface Ethernet0/0 "outside", is up, line protocol is up Hardware is i82546GB rev03, BW 100 Mbps Full-Duplex(Full-duplex), 100 Mbps(100 Mbps) MAC address... (6 Replies)
Discussion started by: irongeekio
6 Replies

3. Shell Programming and Scripting

bash: read file line by line (lines have '\0') - not full line has read???

I am using the while-loop to read a file. The file has lines with null-terminated strings (words, actually.) What I have by that reading - just a first word up to '\0'! I need to have whole string up to 'new line' - (LF, 10#10, 16#A) What I am doing wrong? #make file 'grb' with... (6 Replies)
Discussion started by: alex_5161
6 Replies

4. Shell Programming and Scripting

Remote script skips "read" command

This script is supposed to display a file ( crontab ), ask the user if they wish to update the file, then it goes through an update routine. #!/bin/bash FILE=/etc/crontab tail -5 $FILE echo -n "Does crontab need updating" read HOURS ...routines ....etc... Runs locally... (8 Replies)
Discussion started by: Bubnoff
8 Replies

5. UNIX for Dummies Questions & Answers

Foreach loop that skips the header line of a file (csh)

Hello all, I'm working on a foreach loop to compare a couple sets of data. However, each datafile includes a header row. I'm wondering if it is possible to tell the foreach loop to skip the first line of data. I've been using the basic code as follows: foreach line ("`file.csv`") set... (2 Replies)
Discussion started by: meteorologistks
2 Replies

6. Shell Programming and Scripting

read one line file and separate into multiple lines

I have one long line text with semicolon used as separator between values in that line. Now, I want to separate the line into multiple line right after every 29th field. example input line: ... (2 Replies)
Discussion started by: erlanq
2 Replies

7. Shell Programming and Scripting

read one line file and separate into multiple lines

I have one long line text with semicolon used as separator between values in that line. Now, I want to separate the line into multiple line right after every 29th field. example input line: ... (1 Reply)
Discussion started by: erlanq
1 Replies

8. Shell Programming and Scripting

Read line with particular number of lines

Hi all, I have a file sample.txt abc asd adf daf adw add adv wdf I want to control the number of lines to read Like if i give input as ./script_name 2 5 required output asd adf daf (2 Replies)
Discussion started by: krux_rap
2 Replies

9. Shell Programming and Scripting

Need a program that read a file line by line and prints out lines 1, 2 & 3 after an empty line...

Hello, I need a program that read a file line by line and prints out lines 1, 2 & 3 after an empty line... An example of entries in the file would be: SRVXPAPI001 ERRO JUN24 07:28:34 1775 REASON= 0000, PROCID= #E506 #1065: TPCIPPR, INDEX= 003F ... (8 Replies)
Discussion started by: Ferocci
8 Replies

10. Shell Programming and Scripting

Read the file line by line and do something with lines

I have a file file_name_O.txt The file can have different number of other files names or nothing I will check cnt=`wc -l file_name_0.txt` if ;then exit 1 fi Now I have to start checking file names, i.e. read txt file line by line. If amount of ,lines equal 1, I can... (4 Replies)
Discussion started by: digioleg54
4 Replies
PURITY(6)                                                          Games Manual                                                          PURITY(6)

NAME
purity - a general purpose purity test SYNOPSIS
/usr/games/purity [ flags ] [ testname ] DESCRIPTION
Purity is an interactive purity test program with a simple, user interface and datafile format. For each test, questions are printed to the your terminal, and you are prompted for an answer to the current question. At a prompt, these are your choices: y Answer "yes" to the question. n Answer "no" to the question. b Backup one question, if you answered it incorrectly, or someone is watching you take the test, and you don't (or do) want to admit a different answer. r Redraw the current question. q Quit the test, and print the current score. ? Print a help screen for the current prompt. k Kill a section of the test. This skips all the questions of the test until the next subject heading. a Toggle answer mode between real answers and obfuscated answers. Real answers print "yes" and "no", while obfuscated answers are "Maybe" and "maybe". Obfuscated answers are preferred if you are shy, and don't want people to be able to read your answers over your shoulder as you take the test. d Toggle dERanGe output. s Print your current score on the test you are taking. l Toggle score logging. At the end of the test, your score is printed out. For most purity tests, lower scores denote more "experience" of the test material. FLAGS
These are the command line flags for the test. -a Show real answers (i.e. "yes" and "no") instead of obfuscated ones (i.e. "Maybe" and "maybe") as you answer the questions. -d PrINt THe tESt in DerANgeD pRInT. -f Take the test in fast mode. Only the questions are printed, and not any other text blocks, like the introdution, subject headers, and the conclusion. -l Take the test without having your score logged. -p Print the test without prompting for answers. This is useful for making hard copies of the tests without having to edit out the prompts by hand. -r Decrypt the test using the Rot 13 algorithm. This is done as a form of "protection", such that if you read a rot13 test and it offends you, it's your own fault. -z zoom through more prompts in large text blocks. The default is to prompt the user for more when a screenful of text has been printed without any user input. DATAFILE FORMAT
The format of the datafiles is a very simple format, intended such that new tests can quickly and easily be converted to run with the test. There are four types of text in a purity test datafile. Each type is contained in a bracket type of punctuation. The definitions are as follows: the styles of text blocks are: { plain text block } [ subject header ] ( test question ) and < conclusion > Plain text blocks are printed out character for character. Subject headers are preceded by their subject numbers, starting at 1, and then printed as text blocks. Questions are preceded by their numbers, and then prompt the user to answer the question, keeping track of the user's current score. Conclusions first calculate and print the user's score for the test, then print out the conclusion as a text block. If you wish to include any of the various bracket punctuation in your text, the backslash ("") character will escape the next character. To print a question with parentheses, you would use the following format: (have you ever written a purity test (like this one)?) the output would be this: 1. have you ever written a purity test (like this one)? and then it would have asked the user for her/his answer. For a generic datafile, use the "sample" datafile for the test. FILES
/var/games/purity.scores the score logfile /usr/share/games/purity/* test data files AUTHOR
Eric Lechner, lechner@ucscb.ucsc.edu 18 December 1989 PURITY(6)
All times are GMT -4. The time now is 11:07 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy