Sponsored Content
Full Discussion: Question about I/O sources
Top Forums UNIX for Dummies Questions & Answers Question about I/O sources Post 302750929 by Yoda on Thursday 3rd of January 2013 12:38:23 AM
Old 01-03-2013
Standard input (stdin) normally comes from your keyboard. Many programs ignore stdin.

E.g. cat filename never reads its standard input; it reads the files directly. But without file names on the command line, UNIX commands that need input will usually read stdin.

Standard input normally comes from your keyboard, but the shell can redirect stdin from a file. This is handy for UNIX commands that can't open files directly.

E.g. mail user@domain.com < filename. To mail a file use < filename to tell the shell to attach the file, instead of your keyboard, to mail's standard input.

sed can read file directly, so no need to redirect stdin from a file. I hope this helps.
 

9 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

unix sources

hello, i'm looking for the sources of the old, original unices (v3 preferred). could someone point a link? (2 Replies)
Discussion started by: fdarkangel
2 Replies

2. UNIX for Dummies Questions & Answers

Sources for Raid Information

All, I have worked with UNIX for quite a while but never with raid. My section has just taken control of 3 servers each with different configurations and all running raids. My question for everyone is can you recommend any books that I can purchase or web sites that deal specifically with how to... (1 Reply)
Discussion started by: 3grls=1hd8
1 Replies

3. Linux

Kernel sources

I"m installing my ATI card in FC4. I'm going off of instructions that i've found. The firs step says that i need my kernel sources which i've got then it says that i've gotta unpack them so i can make links to the file later. My kernel sources that i've got are .src.rpm I've installed them but... (1 Reply)
Discussion started by: byblyk
1 Replies

4. Linux

Makefile with sources in diferent folders

Hi guys! I have a problem to create a makefile when using 2 types of sources. Suppose we have sources at master_source folder: - 1.c - 2.c and also we have sources at platform_source folder: - 1.c I really need to use platform_source folder because there is many of them (one folder with... (8 Replies)
Discussion started by: borzh62
8 Replies

5. SuSE

FAILED during patching kernel sources

Hi all. I have an issue with kernel patching. My system: OpenSuse 10.2, kernel version: 2.6.18.2. I've downloaded the patch from kernel.org - 2.6.26. I've invoked the following command: "patch -p1 -f < patch-2.6.26" (-f - because some files are not exist. to automatically skip this issues).... (2 Replies)
Discussion started by: Vourhey
2 Replies

6. News, Links, Events and Announcements

Are the UnixWare 7.1.1 sources available?

So, I was browsing groklaw.net, and I was surprised to read that Pamela Jones was reading the copyright notices in the UnixWare 7.1.1 source code files... Groklaw - Santa Cruz Listed Novell as Owning the Copyrights in 1999 How can that be? Are the UnixWare 7.1.1 sources available to the... (1 Reply)
Discussion started by: pepinox
1 Replies

7. Solaris

Building OpenSolaris from sources

Everyone knows the project LFS (Linux from scratch), it is a book-assembly instructions GNU / Linux from source code. I managed to gather, then my knowledge of GNU / Linux grew, learned many new commands, edit config-files, base packages, kernel, etc. .. Now I would like also to explore... (0 Replies)
Discussion started by: Geekon
0 Replies

8. Debian

Repositories in sources.list

I'm just interested to know how your sources.list look like. I got some repositories witch give some errors and I would like to clean it up. and when I do apt-get update I get few lines showing errors like 404 , this is how my list look like: # deb cdrom:/ squeeze main # deb cdrom:/... (0 Replies)
Discussion started by: zdorian
0 Replies

9. Programming

Can anyone provide some sources about bank IT

I am working in IT company working for banks.I find hardly to get technology about bank IT on the internet.Consider banks all using Unix, I think I can get some help here. Recommend some sits or books about bank IT will be very helpful!! (0 Replies)
Discussion started by: hhdzhu
0 Replies
TRS(1)								Linux User's Manual							    TRS(1)

NAME
trs - filter replacing strings SYNOPSIS
trs [-[r]e] 'REPLACE_THIS WITH_THAT [AND_THIS WITH_THAT]...' trs [-[r]f] FILE DESCRIPTION
Copy stdin to stdout replacing every occurence of given strings with other ones. This is similar to tr(1), but replaces strings, not only single chars. Rules (separated by whitespace) can be given directly after -e option, or can be read from FILE. Argument not preceded by -e or -f is guessed to be a script when it contains some whitespace, or a filename otherwise. Comments are allowed from # until the end of line. The character # in strings must be specified as #. Standard C-like escapes a  e f v \ nn are recognized. In addition, s means a space character and ! means an empty string. Sets of acceptable characters at a given position can be specified between [ and ]. ASCII ranges in sets can be shortly written as FIRST-LAST. When a set consists of only a single range, [ and ] can be omitted. When a part of the string to translate is enclosed in {...}, only that part is replaced. Any text outside {...} serves as an assertion: a string is translated only if it is preceded by the given text and followed by another one. { at the beginning or } at the end of the string can be omitted. Text outside {...} is treated as untranslated. Before the beginning of the file and after its end there are only 's. Thus, for example, {.} matches . on a line by itself, including the first line, and the last one even without the marker. A fragment of the form ?x=N, where x is a letter A-Za-z and N is a digit 0-9, contained in the target text sets the variable x to the value N when that rule succeeds. Similar fragment in the source text causes the given rule to be considered only if that variable has such value. Initially all variables have the value of 0. Several assignments or conditions can be present in one rule - they are ANDed together. OPTIONS -e Give the translation rules directly in the command line. -f Get them from the file specified. -r Reverse every rule. This affects only the next -e or -f option. Of course this doesn't have to give the reverse translation! Any rule containing any of {}[]{}- is taken in only one direction. You may force any rule to be taken in only one direction by enclosing the string to translate in {...}. --help display help and exit --version output version information and exit Multiple -e or -f options are allowed. All rules are loaded together then, and earlier ones have precedence. EXAMPLE
$ echo Leeloo |trs -e 'el n e i i aqq o} x o u' Linux DIFFERENCES FROM sed The main difference between trs and sed 's///g; ...' (excluding sed's regular expressions) is that sed takes every rule in the order speci- fied and applies it to the whole line of translated file, whereas trs examines every position and tries all rules in this place first. In sed every next rule is fed with the text produced by the previous one, whereas in trs every piece of text can be translated at most once (if more than one rule matches at a given position, the one mentioned earlier wins). That's why sed isn't well suited for translating between character sets. On the other hand, tr translates only single bytes, so it can't be used for Unicode conversions, or TeX / SGML ways for specifying extended characters. Another example: $ echo 642 |trs -e '4 7 72 66 64 4' 42 $ echo 642 |sed 's/4/7/g; s/72/66/g; s/64/4/g' 666 The string to replace can be empty; there must be something outside {} then. In this special case only one such create-from-nothing rule can success at a given position. For example, }x80-xFF @ precedes every character with high byte set with @. The rule of the form some{ thing doesn't work at the end of a file. SEE ALSO
tr(1), konwert(1) COPYRIGHT
trs is a filter replacing strings. It forms part of the konwert package. Copyright (c) 1998 Marcin 'Qrczak' Kowalczyk This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MER- CHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA AUTHOR
__("< Marcin Kowalczyk * qrczak@knm.org.pl http://qrczak.home.ml.org/ \__/ GCS/M d- s+:-- a21 C+++>+++$ UL++>++++$ P+++ L++>++++$ E->++ ^^ W++ N+++ o? K? w(---) O? M- V? PS-- PE++ Y? PGP->+ t QRCZAK 5? X- R tv-- b+>++ DI D- G+ e>++++ h! r--%>++ y- Konwert 12 Jul 1998 TRS(1)
All times are GMT -4. The time now is 02:30 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy