Sponsored Content
Full Discussion: loops with tr
Top Forums UNIX for Dummies Questions & Answers loops with tr Post 302346930 by juliette salexa on Monday 24th of August 2009 12:25:07 PM
Old 08-24-2009
loops with tr

Hello,

I'm not sure if this is more appropriate for the 'unix for dummies' or the 'unix for experts' forum because I'm new to this forum and this is the second topic I've discussed, but if you could let me know which one was more appropriate for something like this, please do!

So in tr (an ancient UNIX application), I can join all lines of a text file into one line by doing this:

Code:
tr -d '\n' <x >y

where x is the original file name with extension, and y is the new one.

This is about 10^6 times faster than the command %join! in vi, and doesn't leave a '\n' at the end.

-------------------
My question is, how to do this in a loop, say for all files beginning with a, and keep the filenames the same.
The following doesn't work:

Code:
for file in a*; do tr -d '\n' <"$file" >"$file"; done

This just turns a* into blank files.


I have a feeling that the problem is with the "$file" part, since tr might have a different format for the file name, but I'm not so familiar with tr

If anyone knows a way around this I would be very thankful Smilie
Thanks in advance!
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

loops?

hello....very new user to unix...and i have a question..i am not sure if there is such a thing For example...the user is asked if he likes Bananas....if he says yes.... echo You like Bananas $name at the end of the script it echos all that the user has entered so they can read it.... but... (1 Reply)
Discussion started by: jonas27
1 Replies

2. Shell Programming and Scripting

Loops within loops

I am running on HPUX using ksh. I have a script that uses a loop within a loop, for some reason the script seems to hang on a particuliar record. The record is fine and hits the condition in Blue. If I kill the 1st loop process the script continues on with no problem. Begin code> <Some... (8 Replies)
Discussion started by: bthomas
8 Replies

3. UNIX for Dummies Questions & Answers

While Loops

I'm trying to create a loop that will prompt the user for 15 values, not forcing them to enter all 15. If the user enters through one or more of the prompts the null value needs to be converted to 0, otherwise set the parameter = to the value entered: ex. Please enter file no #1: 17920 ... (4 Replies)
Discussion started by: vdc
4 Replies

4. UNIX for Dummies Questions & Answers

two loops

Hi, how can I use "for" to have two loops : this is my script : for i in (A B C) do for j in (a b c) do echo $i$j done done #End I want to print out Aa Ab Ac .... But I have error message : syntax error at line 1 : `(' unexpected Many thanks before. How should I use "for" ?? (2 Replies)
Discussion started by: big123456
2 Replies

5. Shell Programming and Scripting

while loops

Hi I've a file like so: Now, I want to read my file and take ex. the Media ID and the Type for each groups of Media (Media1,Media2,...,Media(n): cat /tmp/file|\ while read FILE do while $(FILE|cut -d: -f1)=Media$i do #here will be some test, ex: #if Media ID < 23 ... (4 Replies)
Discussion started by: nymus7
4 Replies

6. UNIX for Dummies Questions & Answers

Help with While Loops

I am traversing down a list, and I am not quite sure how to tell the loop to break when it's done going through the file. #!/bin/sh while : do read list <&3 echo $list done is the code. The file "list" is simply 5 4 3 2 1 any advice on how to break the loop after the file is... (1 Reply)
Discussion started by: MaestroRage
1 Replies

7. Shell Programming and Scripting

Help with the 2 for loops

#!/bin/bash IFS=$'\n' A= a c b t g j i e d B= t y u i o p counter=0 found="" for i in $(cat $A) do for j in $(cat $B) do if then found="yes" fi done if then (1 Reply)
Discussion started by: vadharah
1 Replies

8. Shell Programming and Scripting

Loops

Hi All, I want to execute a script the number of times a user enters. Please can you advise on hor can I do the same. Many Thanks, Shazin (4 Replies)
Discussion started by: Shazin
4 Replies

9. UNIX for Advanced & Expert Users

Help with loops?

I'm trying to understand better the while and until loops, can someone help me with this example? #!/bin/bash # Listing the planets. for planet in Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Pluto do echo $planet # Each planet on a separate line. done echo; echo for... (3 Replies)
Discussion started by: jose2802
3 Replies

10. UNIX for Dummies Questions & Answers

Need help with for loops

Why wont my for statements work? Im trying to get this script to swich to a user an if you put in a start/stop/or restart paramater to do just that for each user. I commented out the actual start/stop actions to test it just by using echos and not do anything hasty in the environment but it... (0 Replies)
Discussion started by: LilyClaro
0 Replies
IRSEND(1)							   User Commands							 IRSEND(1)

NAME
irsend - basic LIRC program to send infra-red commands SYNOPSIS
irsend [options] DIRECTIVE REMOTE CODE [CODE...] DESCRIPTION
Asks the lircd daemon to send one or more CIR (Consumer Infra-Red) commands. This is intended for remote control of electronic devices such as TV boxes, HiFi sets, etc. DIRECTIVE can be: SEND_ONCE - send CODE [CODE ...] once SEND_START - start repeating CODE SEND_STOP - stop repeating CODE LIST - list configured remote items SET_TRANSMITTERS - set transmitters NUM [NUM ...] SIMULATE - simulate IR event REMOTE is the name of a remote, as described in the lircd configuration file. CODE is the name of a remote control key of REMOTE, as it appears in the lircd configuration file. NUM is the transmitter number of the hardware device. For the LIST DIRECTIVE, REMOTE and/or CODE can be empty: LIST "" "" - list all configured remote names LIST REMOTE "" - list all codes of REMOTE LIST REMOTE CODE - list only CODE of REMOTE The SIMULATE command only works if it has been explicitly enabled in lircd. -h --help display usage summary -v --version display version -d --device use given lircd socket [/var/run/lirc/lircd] -a --address=host[:port] connect to lircd at this address -# --count=n send command n times EXAMPLES
irsend LIST DenonTuner "" irsend SEND_ONCE DenonTuner PROG-SCAN irsend SEND_ONCE OnkyoAmpli VOL-UP VOL-UP VOL-UP VOL-UP irsend SEND_START OnkyoAmpli VOL-DOWN ; sleep 3 irsend SEND_STOP OnkyoAmpli VOL-DOWN irsend SET_TRANSMITTERS 1 irsend SET_TRANSMITTERS 1 3 4 irsend SIMULATE "0000000000000476 00 OK TECHNISAT_ST3004S" FILES
/etc/lirc/lircd.conf Default lircd configuration file. It should contain all the remotes, their infra-red codes and the corresponding timing and wave- form details. DIAGNOSTICS
If lircd is not running (or /var/run/lirc/lircd lacks write permissions) irsend aborts with the following diagnostics: "irsend: could not connect to socket" "irsend: Connection refused" (or "Permission denied"). SEE ALSO
The documentation for lirc is maintained as html pages. They are located under html/ in the documentation directory. lircd(8), mode2(1), smode2(1), xmode2(1), irrecord(1), irw(1), http://www.lirc.org. irsend 0.9.0-pre1 October 2010 IRSEND(1)

Featured Tech Videos

All times are GMT -4. The time now is 07:30 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy