Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Basic grep question
Top Forums Shell Programming and Scripting Basic grep question Post 303002507 by kraljic on Saturday 26th of August 2017 01:50:11 AM
Old 08-26-2017
Basic grep question
Shell : Bash shell (Fedora 26)

In the below text file (output.txt), I need to find all lines starting with the pattern pc. As you can see, only one line matches this condition (pc hello world).

But, my below 3 attempts return wrong output. How do I use the grep command correctly here ?


Code:
 # cat output.txt
  sunrpc                331776  1
  crct10dif_pclmul       16384  0
  crc32_pclmul           16384  0
  shpchp                 36864  0
  snd_pcm               102400  4 snd_hda_intel,snd_hda_codec,snd_hda_core,snd_hda_codec_hdmi
  snd_timer              32768  2 snd_seq,snd_pcm
  lpc_ich                24576  0
  pc hello world

  # Attempt1
  # It returns any line with the the pattern pc in it which is not what I want
  # grep 'pc' output.txt
  sunrpc                331776  1
  crct10dif_pclmul       16384  0
  crc32_pclmul           16384  0
  shpchp                 36864  0
  snd_pcm               102400  4 snd_hda_intel,snd_hda_codec,snd_hda_core,snd_hda_codec_hdmi
  snd_timer              32768  2 snd_seq,snd_pcm
  lpc_ich                24576  0
  pc hello world
  # 


  # Attempt2
  # No output returned at all
  # grep 'pc^' output.txt



  # Attempt3 
  # I think this gives the same wrong output as Attempt1 
  # grep 'pc*' output.txt
  sunrpc                331776  1
  crct10dif_pclmul       16384  0
  crc32_pclmul           16384  0
  shpchp                 36864  0
  snd_pcm               102400  4 snd_hda_intel,snd_hda_codec,snd_hda_core,snd_hda_codec_hdmi
  snd_timer              32768  2 snd_seq,snd_pcm
  lpc_ich                24576  0
  pc hello world
  #

 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

basic question

I have some basic doubts. Can someone clarify in this forum? 1)if then eval ' tset -s -Q -m ':?hp' ' else eval ' tset -s -Q ' what does it exactly mean in .profile? 2) what are 'nobody' and 'noaccess' usernames in /etc/passwd file. ... (3 Replies)
Discussion started by: asutoshch
3 Replies

2. UNIX for Dummies Questions & Answers

basic question

hey...when i type who...what does "pts" field mean??? eg pts 0 etc (1 Reply)
Discussion started by: urwannabefriend
1 Replies

3. UNIX for Dummies Questions & Answers

Very Basic Question

How to know if my AIX 5.2 is running at 64bits? THANKS (5 Replies)
Discussion started by: GermanSkull
5 Replies

4. UNIX for Dummies Questions & Answers

Really basic question....

Hello all. Let me start off by saying I know a little more then it seems by me asking this question... here goes I have an old 486 box and I want to start messing around with unix. I've been taking classes for 3 or 4 years in c programming in unix, so I am used to the commands and such, but I... (1 Reply)
Discussion started by: robherms
1 Replies

5. HP-UX

Basic OS question

Could someone tell me the command to find out the OS version which will give 12 character not the 9 characters(which is usually machine id). uname -i gives machine id and uname -a is more comprehensive way to look. Thanks! (4 Replies)
Discussion started by: catwomen
4 Replies

6. Shell Programming and Scripting

basic question

hi, I have a basic question,, i am in a directory called /intas/OCU_3.9.1/sbin ocuut1@france>mv itsa_tcs itsa_tcs_old mv: itsa_tcs_old: rename: Permission denied i am logging as the owner of the file. when i am doing this i am getting the above error of permission denied. I know... (3 Replies)
Discussion started by: namishtiwari
3 Replies

7. Shell Programming and Scripting

basic nc question

i'm doing this in one terminal: nc -lu 7402 and it appears to start listening properly, then in another i do this: echo "hello" | nc -u localhost 7402 and nothing happens on the listening terminal - what am i doing wrong? thanks. (7 Replies)
Discussion started by: peterworth
7 Replies

8. Shell Programming and Scripting

basic grep question

I think I am doing this correctly, but it is responding very quickly with no results so I am not sure. I need to do a case insensitive grep of all files in my current directory grep -i <keyword> /my/directory is that correct? (1 Reply)
Discussion started by: guessingo
1 Replies

9. Shell Programming and Scripting

Basic Grep

I am trying to grep a section of .txt file...but once I grep the certain area of the file I would like to display all lines below it as well....how do I have to go about doing this... example grep "Sidney Crosby" hockey.txt result Sidney Crosby Age Goals Assist Can this be done... (8 Replies)
Discussion started by: chrisp200
8 Replies

10. Shell Programming and Scripting

Basic grep -c Question

Hello, I have a csv list which contains a reference and tariff code for every customer we have (~7.2 million) looking something like this: customernumber,tariff 012345678910,T0001 012345678911,T0002 012345678912,T0001-A0001 I have a 2nd list which contains every unique tariff and... (8 Replies)
Discussion started by: Cludgie
8 Replies

LEARN ABOUT REDHAT

dos2unix

dos2unix(1)						      General Commands Manual						       dos2unix(1)

NAME

       dos2unix - DOS/MAC to UNIX text file format converter

SYNOPSYS

       dos2unix [options] [-c convmode] [-o file ...] [-n infile outfile ...]

       Options:

       [-hkqV] [--help] [--keepdate] [--quiet] [--version]

DESCRIPTION

       This manual page documents dos2unix, the program that converts plain text files in DOS/MAC format to UNIX format.

OPTIONS

       The following options are available:

       -h --help
	      Print online help.

       -k --keepdate
	      Keep the date stamp of output file same as input file.

       -q --quiet
	      Quiet mode. Suppress all warning and messages.

       -V --version
	      Prints version information.

       -c --convmode convmode
	      Sets conversion mode. Simulates dos2unix under SunOS.

       -o --oldfile file ...
	      Old file mode. Convert the file and write output to it. The program default to run in this mode. Wildcard names may be used.

       -n --newfile infile outfile ...
	      New  file  mode.	Convert the infile and write output to outfile. File names must be given in pairs and wildcard names should NOT be
	      used or you WILL lost your files.

EXAMPLES

       Get input from stdin and write output to stdout.

	      dos2unix

       Convert and replace a.txt. Convert and replace b.txt.

	      dos2unix a.txt b.txt

	      dos2unix -o a.txt b.txt

       Convert and replace a.txt in ASCII conversion mode.  Convert and replace b.txt in ISO conversion mode.  Convert	c.txt  from  Mac  to  Unix
       ascii format.

	      dos2unix a.txt -c iso b.txt

	      dos2unix -c ascii a.txt -c iso b.txt

	      dos2unix -c mac a.txt b.txt

       Convert and replace a.txt while keeping original date stamp.

	      dos2unix -k a.txt

	      dos2unix -k -o a.txt

       Convert a.txt and write to e.txt.

	      dos2unix -n a.txt e.txt

       Convert a.txt and write to e.txt, keep date stamp of e.txt same as a.txt.

	      dos2unix -k -n a.txt e.txt

       Convert and replace a.txt. Convert b.txt and write to e.txt.

	      dos2unix a.txt -n b.txt e.txt

	      dos2unix -o a.txt -n b.txt e.txt

       Convert c.txt and write to e.txt. Convert and replace a.txt.  Convert and replace b.txt. Convert d.txt and write to f.txt.

	      dos2unix -n c.txt e.txt -o a.txt b.txt -n d.txt f.txt

DIAGNOSTICS

BUGS

       The program does not work properly under MSDOS in stdio processing mode.  If you know why is that so, please tell me.

AUTHORS

       Benjamin Lin - <blin@socs.uts.edu.au>

       Bernd Johannes Wuebben (mac2unix mode) <wuebben@kde.org>

MISCELLANY

       Tested environment:

	      Linux 1.2.0 with GNU C 2.5.8

	      SunOS 4.1.3 with GNU C 2.6.3

	      MS-DOS 6.20 with Borland C++ 4.02

       Suggestions and bug reports are welcome.

SEE ALSO

       unix2dos(1) mac2unix(1)

1995.03.31							   dos2unix v3.0						       dos2unix(1)
All times are GMT -4. The time now is 12:59 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy