The efficiency between GREP and SED??? Post: 302452885

5 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

efficiency..

how efficient is it, and how practical is it to call outside programs in a shell script (bash) for small tasks? for example, say i have a script that might preform many tasks, one of those tasks may require root access; rather than implementing inside the script a method to use su or sudo to...

2. Shell Programming and Scripting

Perl: code efficiency for gmtime

I have the following Perl snippet: # get datetime @dt = gmtime(); $strdate = 1900 + $dt . addleadingzero(++$dt) . addleadingzero($dt) . addleadingzero($dt) . addleadingzero($dt) . addleadingzero($dt); # write to file $outfile = $strdate . ".txt"; getstore($url, $outfile) or die "Error:...

3. Shell Programming and Scripting

Improve program efficiency (awk)

Hi !! I've finished an awk exercise. Here it is: #!/bin/bash function calcula { # Imprimimos el mayor tama�o de fichero ls -l $1 | awk ' BEGIN { max = $5; # Inicializamos la variable que nos guardar� el m�ximo con el tama�o del primer archivo } { if ($5 > max){ #...

4. Shell Programming and Scripting

File or Folder Efficiency?

I've got this program set up so that it creates files whose unique names specify the jobs their contents describe. In order to retrieve the information inside those files, I have to do a "grep" and awk or sed to extract it. I've just assumed that making a directory with that unique name that...

5. UNIX for Advanced & Expert Users

About efficiency of parallel memory allocation

Hello, there. I'm a new beginner to Linux kernel and curious about its memory management. When multiple applications apply for memory space at the same time, how Linux kernel solve the resource contending problem for high performance? I have known that there is a buddy system for allocating and...

LEARN ABOUT NETBSD

re_comp

RE_COMP(3)						   BSD Library Functions Manual 						RE_COMP(3)

NAME

     re_comp, re_exec -- regular expression handler

LIBRARY

     Compatibility Library (libcompat, -lcompat)

SYNOPSIS

     #include <re_comp.h>

     char *
     re_comp(const char *s);

     int
     re_exec(const char *s);

DESCRIPTION

     This interface is made obsolete by regex(3).  It is available from the compatibility library, libcompat.

     The re_comp() function compiles a string into an internal form suitable for pattern matching.  The re_exec() function checks the argument
     string against the last string passed to re_comp().

     The re_comp() function returns 0 if the string s was compiled successfully; otherwise a string containing an error message is returned.  If
     re_comp() is passed 0 or a null string, it returns without changing the currently compiled regular expression.

     The re_exec() function returns 1 if the string s matches the last compiled regular expression, 0 if the string s failed to match the last
     compiled regular expression, and -1 if the compiled regular expression was invalid (indicating an internal error).

     The strings passed to both re_comp() and re_exec() may have trailing or embedded newline characters; they are terminated by NULs.	The regu-
     lar expressions recognized are described in the manual entry for ed(1), given the above difference.

DIAGNOSTICS

     The re_exec() function returns -1 for an internal error.

     The re_comp() function returns one of the following strings if an error occurs:

	   No previous regular expression,
	   Regular expression too long,
	   unmatched (,
	   missing ],
	   too many () pairs,
	   unmatched ).

SEE ALSO

     ed(1), egrep(1), ex(1), fgrep(1), grep(1), regex(3)

HISTORY

     The re_comp() and re_exec() functions appeared in 4.0BSD.

BSD
								   June 4, 1993 							       BSD