Berkeley CSUA MOTD:Entry 23113
Berkeley CSUA MOTD
 
WIKI | FAQ | Tech FAQ
http://csua.com/feed/
2025/07/09 [General] UID:1000 Activity:popular
7/9     

2001/11/27-28 [Computer/SW/Languages/C_Cplusplus, Computer/SW/Languages/Perl, Computer/SW/Unix] UID:23113 Activity:nil
11/26   How do I find file and symlink only that excludes a, b, and c?
        I tried: find . \( -type f -o -type l \) -name a -prune -o
                        -name b -prune -name c -prune -o -print
        and failed miserably.
        \_ find . \( -type f -o -type l \) -print | egrep -v '^(a|b|c)$'
        \_ perl
2025/07/09 [General] UID:1000 Activity:popular
7/9     

You may also be interested in these entries...
2014/1/14-2/5 [Computer/SW/Languages/C_Cplusplus] UID:54763 Activity:nil
1/14    Why is NULL defined to be "0" in C++ instead of "((void *) 0)" like in
        C?  I have some overloaded functtions where one takes an integer
        parameter and the other a pointer parameter.  When I call it with
        "NULL", the compiler matches it with the integer version instead of
        the pointer version which is a problem.  Other funny effect is that
        sizeof(NULL) is different from sizeof(myPtr).  Thanks.
	...
2013/4/9-5/18 [Computer/SW/Languages/C_Cplusplus, Computer/SW/Apps, Computer/SW/Languages/Perl] UID:54650 Activity:nil
4/04    Is there a good way to diff 2 files that consist of columns of
        floating point numbers, such that it only tells me if there's a
        difference if the numbers on a given line differ by at least a given
        ratio?  Say, 1%?
        \_ Use Excel.
           1. Open foo.txt in Excel.  It should convert all numbers to cells in
	...
2013/4/29-5/18 [Computer/SW/Languages/C_Cplusplus, Computer/SW/Compilers] UID:54665 Activity:nil
4/29    Why were C and Java designed to require "break;" statements for a
        "case" section to terminate rather than falling-through to the next
        section?  99% of the time poeple want a "case" section to terminate.
        In fact some compilers issue warning if there is no "break;" statement
        in a "case" section.  Why not just design the languages to have
        termination as the default behavior, and provide a "fallthru;"
	...
2012/7/19-11/7 [Computer/SW/Languages/C_Cplusplus] UID:54439 Activity:nil
7/19    In C or C++, how do I write the code of a function with variable
        number of parameters in order to pass the variable parameters to
        another function that also has variable number of parameters?  Thanks.
        \_ The usual way (works on gcc 3.0+, Visual Studio 2005+):
               #define foo(fmt, ...) printf(fmt, ##__VA_ARGS__)
           The cool new way (works on gcc 4.3+):
	...
2011/3/7-4/20 [Computer/SW/Languages/C_Cplusplus] UID:54056 Activity:nil
3/7     I have a C question.  I have the following source code in two identical
        files t.c and t.cpp:
                #include <stdlib.h>
                int main(int argc, char *argv[]) {
                  const char * const * p1;
                  const char * * p2;
	...
2011/2/5-19 [Computer/SW/Languages/C_Cplusplus] UID:54027 Activity:nil
2/4     random C programming/linker fu question.  If I have
        int main() { printf("%s is at this adddr %p\n", "strlen", strlen); }
        and soda's /proc/sys/kernel/randomize_va_space is 2 (eg; on)
        why is strlen (or any other libc fn) at the same address every time?
        \_ I don't pretend to actually know the right answer to this, but
           could it have something to do with shared libraries?
	...
2010/2/12-3/9 [Computer/SW/Languages/C_Cplusplus] UID:53708 Activity:nil
2/12    I need a way to make a really big C++ executable (~200MBs) that does
        nothing.  No static initialization either.  Any ideas?
        \_ static link in lots of libraries?
        \_ #define a   i=0; i=0; i=0; i=0; i=0; i=0; i=0; i=0; i=0; i=0;
           #define b   a a a a a a a a a a
           #define c   b b b b b b b b b b
	...
2009/9/28-10/8 [Computer/SW/Languages/C_Cplusplus] UID:53409 Activity:nil
9/28    http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html
        Java is #1!!! Followed by C, PHP, C++, Visual Basic, Perl,
        C#, Python, Javascript, then finally Ruby. The good news is
        Pascal is going waaaay back up!
        \_ C is still more popular than C++?  I feel much better about myself
           now.
	...
2009/8/7-14 [Computer/SW/Languages/C_Cplusplus, Computer/SW/Languages/Java] UID:53252 Activity:high
8/6     In C one can do "typedef int my_index_t;".  What's the equivalent in
        C#?  Thanks.
        \_ C#? Are you serious? Is this what the class of 2009 learn?
           \_ No.  I have to learn .NET code at work.  I am Class of '93.
           \_ python is what 2009 learns, see the motd thread about recent
              cal courses and languages
	...
2009/7/21-24 [Computer/SW/Languages/Java] UID:53168 Activity:moderate
7/20    For those who care btw, it looks like eclipse is now A Standard Tool
        at UCB ugrad cs, probably replaced emacs.  Furthermore, people get
        angry at seeing Makefiles, (since eclispe takes care of that).  I
        guess it's just a sign of the times.
        \_ The more people at my work use eclipse the less the code is
           managable in emacs.  I'm not sure which application's fault
	...
2011/10/26-12/6 [Computer/SW/Unix] UID:54202 Activity:nil
10/24  What's an easy way to see if say column 3 of a file matches a list of
       expressions in a file? Basically I want to combine "grep -f <file>"
       to store the patterns and awk's $3 ~ /(AAA|BBB|CCC)/ ... I realize
       I can do this with "egrep -f " and use regexp instead of strings, but
       was wondering if there was some magic way to do this.
       \_ UNIX has no magic. Make a shell script to produce the ask or egrep
	...
2008/7/14-16 [Computer/SW/Languages/Perl, Computer/SW/Unix] UID:50557 Activity:moderate
7/14    Shell Programming question: I want to call a script with 1 arg
        and have it figure out whether $1 is a MAC address or an IP address
        and then do call the appropriate function.  What is the best way
        to do this, given that sh/bash/ksh do not have something like
        the =~ in perl.  Check for exit status of grep, or is there a
        a better way?  For the moment, let's just say the two tests are:
	...
2005/3/2-3 [Computer/SW/Unix] UID:36496 Activity:high
3/2     Is there a way to do "grep p1 file | grep p2" with one grep without
        piping? ie, "grep p1&&p2 file"? Thx.
        \_ use egrep?  man egrep.  Look for egrep -e
           \_ Can I write an alias where I can say "mygrep p1 p2 p3 ... file",
              where I can specify variable number of patterns, with the last
              one being the filename?
	...
2004/9/14 [Computer/SW/Unix] UID:33516 Activity:moderate 50%like:35981
9/13    How can I get grep to serach for the characters '--' or '->'
        (without the single quotes)? grep '--' * doesn't work. Thanks.
        \- egrep -e  '<expression>'  --psb
        \_ grep -- '--' *
           (the first -- indicates the end of the list of options)
	...
2004/5/31 [Computer/SW/Languages/Perl] UID:30503 Activity:insanely high
5/30    Let's say I have a directory full of subdirectories, each of which
        has a number of files in it. How can I delete all subdirectories that
        have, say, less than 10 files in them?
                   \_ fewer
        \_ There's no single standard command that will do this.  You'll
           need to write something that will count files per directory,
	...
2004/3/23-24 [Computer/SW/Unix] UID:12817 Activity:very high
3/23    What's the easiest way to find all files on a unix box that contain
        both the words 'imap' and 'pop' on different lines. I'm trying to
        find a courier authd config file that I swear had lines for turning
        on and off different protocols (pop3 and imapd) but I can't find it
        anywhere. and I can't find any references to it. -brett
        \_ hrm.
	...
2003/6/10-11 [Computer/SW/Unix] UID:28691 Activity:high
6/10    I want to grep for the ocurrance of the ']' and '[' character in a file
        I've tried all sorts of quoting on the command line, everything seems
        to give a ayntax or 'unmatched' error. How can I do this?
        \_ grep '\['
        \_ to search for both, use "egrep '\[|\]'<filename>" -jnat
           \_ That doesn't seem to work as an "or" perhaps the version
	...
2003/5/5-6 [Computer/SW/Unix] UID:28340 Activity:high
5/5     Given a file, what is the best way to see all lines AFTER (and
        including) a keyword?
        \_ sed -n '/keyword/,$p' file
        \_ agrep?
        \_ perl -ne 'if ($p) {print;} elsif (/keyword/) {$p=1;print;}' file
           \_ thanks.  When do you use perl, sed, awk, egrep?
	...
2002/11/15-16 [Computer/SW/Unix] UID:26553 Activity:moderate
11/15   I want to remove all lines in a tex file that have been commented out
        by a % at the beginning  Any fast and easy way to do this?
        Sorry no time to RTFM.  Ok tnx.
        \_ egrep -v '^\%' file > file.new
           \_ grep -v ^% file > file.new
              conserve keystrokes.  ride bike
	...