Re: [vox-tech] Using awk or perl to find and replace
On Tuesday 23 November 2004 23:41, Foo Lim wrote:
On Tue, 23 Nov 2004, Trevor M. Lango wrote:
I have been reading the man pages and I'm lost. I want to scan through
an input file for an expression with this pattern:
h.*.JPG
and replace it with an expression with the following pattern:
*.h.JPG
Perl and awk both appear to be ideal candidates for just such a task
but I'm a serious newbie to both of 'em. Any help much appreciated!
Hi Trevor,
Does the pattern h.*.JPG match something like this: h.abc123.JPG ?
Something like this: h.#-##--.###.JPG
Since the period . is a metacharacter in regular expressions. If that's
the case, then a perl script like this would work:
while () {
s/h\.(.*)\.JPG/$1.h.JPG/g;
print;
}
FL
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Re: [vox-tech] Using awk or perl to find and replace
On Wed, 24 Nov 2004, Trevor M. Lango wrote:
On Tuesday 23 November 2004 23:41, Foo Lim wrote:
On Tue, 23 Nov 2004, Trevor M. Lango wrote:
I have been reading the man pages and I'm lost. I want to scan through
an input file for an expression with this pattern:
h.*.JPG
and replace it with an expression with the following pattern:
*.h.JPG
Perl and awk both appear to be ideal candidates for just such a task
but I'm a serious newbie to both of 'em. Any help much appreciated!
Hi Trevor,
Does the pattern h.*.JPG match something like this: h.abc123.JPG ?
Something like this: h.#-##--.###.JPG
Since the period . is a metacharacter in regular expressions. If that's
the case, then a perl script like this would work:
while () {
s/h\.(.*)\.JPG/$1.h.JPG/g;
print;
}
FL
The code above should work. If it's possible to have multiple files on a
line, you may want to change the regex to this:
s/h\.(.*?)\.JPG/$1.h.JPG/g;
instead, so it will minimal match instead of do a greedy match.
HTH,
FL
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[vox-tech] Understanding a C hello world program
Consider this program:
#includestdio.h
int main(void)
{
printf(hello world\n);
return 0;
}
The more I think about it, the more fascinated I am by it. I can get the
length of the sections using the size command:
[EMAIL PROTECTED] size hello_world-1.o
textdata bss dec hex filename
48 0 0 48 30 hello_world-1.o
I assume that data is the initialized data segment where programmer
initialized variables are stored. That's zero because I have no global
variables.
I also assume that bss is zero because I have no programmer-uninitialized
global variables.
When I disassemble the object file, I get 35 bytes:
Dump of assembler code for function main:
0x main+0:push %ebp
0x0001 main+1:mov%esp,%ebp
0x0003 main+3:sub$0x8,%esp
0x0006 main+6:and$0xfff0,%esp
0x0009 main+9:mov$0x0,%eax
0x000e main+14: sub%eax,%esp
0x0010 main+16: movl $0x0,(%esp)
0x0017 main+23: call 0x18 main+24
0x001c main+28: mov$0x0,%eax
0x0021 main+33: leave
0x0022 main+34: ret
End of assembler dump.
however, size reports a text size of 48. Where do the extra 13 bytes come
from that size reports? Probably from hello world\n\0, which is 13 bytes.
But if that's true, the string lives in the text segment. I always pictured
the text segment as being straight opcodes. There must be a structure to the
text segment that I was unaware of.
But then, looking at the output of the picture that objdump has of the object
file...
[EMAIL PROTECTED] objdump -h hello_world-1.o
hello_world-1.o: file format elf32-i386
Sections:
Idx Name Size VMA LMA File off Algn
0 .text 0023 0034 2**2
CONTENTS, ALLOC, LOAD, RELOC, READONLY, CODE
1 .data 0058 2**2
CONTENTS, ALLOC, LOAD, DATA
2 .bss 0058 2**2
ALLOC
3 .rodata 000d 0058 2**0
CONTENTS, ALLOC, LOAD, READONLY, DATA
4 .note.GNU-stack 0065 2**0
CONTENTS, READONLY
5 .comment 0026 0065 2**0
CONTENTS, READONLY
I wish objdump identified hex numbers as hex numbers. In any event, the text
section has length x23, which is 35. The opcodes plus the string. Further
evidence that the string lives in the text segment.
However, I note that there's a section called .rodata, which I've never heard
of before, but I'm assumming that it stands for read only data section.
It's 13 bytes - just the size of hello world\n\0. That's probably why this
program segfaults:
#includestdio.h
int main(void)
{
char *string=hello world\n;
string[3] = 'T';
puts(string);
return 0;
}
because string is the address of something that lives in a section of memory
marked read-only. Whammo -- sigsegv. I remember Mark posting about 3 or 4
years ago that this actually worked on some other Unicies (not Linux).
There was originally a question attached to this email, but as I typed more
and more, I realized I'm not even sure what my question is anymore. Maybe I
have too many of them.
Maybe my immediate question is -- where do read-only strings live? In the
text section or the .rodata section? I've seen evidence that it lives in
both section.
If anyone cares to riff off this, I'd certainly be interested in anything
anyone says.
Pete
--
The mathematics of physics has become ever more abstract, rather than more
complicated. The mind of God appears to be abstract but not complicated.
He also appears to like group theory. -- Tony Zee's Fearful Symmetry
PGP Fingerprint: B9F1 6CF3 47C4 7CD8 D33E 70A9 A3B9 1945 67EA 951D
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Re: [vox-tech] Using awk or perl to find and replace
On Wednesday 24 November 2004 00:15, Foo Lim wrote:
On Wed, 24 Nov 2004, Trevor M. Lango wrote:
On Tuesday 23 November 2004 23:41, Foo Lim wrote:
On Tue, 23 Nov 2004, Trevor M. Lango wrote:
I have been reading the man pages and I'm lost. I want to scan
through an input file for an expression with this pattern:
h.*.JPG
and replace it with an expression with the following pattern:
*.h.JPG
Perl and awk both appear to be ideal candidates for just such a task
but I'm a serious newbie to both of 'em. Any help much appreciated!
Hi Trevor,
Does the pattern h.*.JPG match something like this: h.abc123.JPG ?
Something like this: h.#-##--.###.JPG
Since the period . is a metacharacter in regular expressions. If
that's the case, then a perl script like this would work:
while () {
s/h\.(.*)\.JPG/$1.h.JPG/g;
print;
}
FL
The code above should work. If it's possible to have multiple files on a
line, you may want to change the regex to this:
s/h\.(.*?)\.JPG/$1.h.JPG/g;
instead, so it will minimal match instead of do a greedy match.
Okay I am not having any success. Perhaps I need to be more specific - I am
trying to scan through html files to replace the image references in lines
like this one:
img align=right src=/IMAGES/C/h.I-LP-CEUR-AD.003.jpg
In this particular example, I need to replace:
h.I-LP-CEUR-AD.003.jpg
with:
I-LP-CEUR-AD.003.h.jpg
Thank you for your responses!
HTH,
FL
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Re: [vox-tech] Using awk or perl to find and replace
On Wed, Nov 24, 2004 at 08:57:03AM -0800, Trevor M. Lango wrote:
On Wednesday 24 November 2004 00:15, Foo Lim wrote:
On Wed, 24 Nov 2004, Trevor M. Lango wrote:
On Tuesday 23 November 2004 23:41, Foo Lim wrote:
On Tue, 23 Nov 2004, Trevor M. Lango wrote:
I have been reading the man pages and I'm lost. ?I want to scan
through an input file for an expression with this pattern:
? ? h.*.JPG
and replace it with an expression with the following pattern:
? ? *.h.JPG
Perl and awk both appear to be ideal candidates for just such a task
but I'm a serious newbie to both of 'em. ?Any help much appreciated!
Hi Trevor,
Does the pattern h.*.JPG match something like this: h.abc123.JPG ?
Something like this: h.#-##--.###.JPG
Since the period . is a metacharacter in regular expressions. If
that's the case, then a perl script like this would work:
while () {
s/h\.(.*)\.JPG/$1.h.JPG/g;
print;
}
FL
The code above should work. If it's possible to have multiple files on a
line, you may want to change the regex to this:
s/h\.(.*?)\.JPG/$1.h.JPG/g;
instead, so it will minimal match instead of do a greedy match.
Okay I am not having any success. Perhaps I need to be more specific - I am
trying to scan through html files to replace the image references in lines
like this one:
img align=right src=/IMAGES/C/h.I-LP-CEUR-AD.003.jpg
In this particular example, I need to replace:
h.I-LP-CEUR-AD.003.jpg
with:
I-LP-CEUR-AD.003.h.jpg
Thank you for your responses!
Capitalization counts. If the files are named with a .jpg, then your
regexp pattern has to say .jpg. If the files are named with a .JPG,
then your regexp pattern has to say .JPG. There is a flag that you can
add at the end (were the g is) to do a case insensitive match, but not
to do a case insensitive, but not to make the replacement string case
insensitive.
--
I usually have a GPG digital signature included as an attachment.
See http://www.gnupg.org/ for info about these digital signatures.
signature.asc
Description: Digital signature
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Re: [vox-tech] Using awk or perl to find and replace
On Wed, 24 Nov 2004, Ken Bloom wrote: On Wed, Nov 24, 2004 at 08:57:03AM -0800, Trevor M. Lango wrote: s/h\.(.*?)\.JPG/$1.h.JPG/g; instead, so it will minimal match instead of do a greedy match. Okay I am not having any success. Perhaps I need to be more specific - I am trying to scan through html files to replace the image references in lines like this one: img align=right src=/IMAGES/C/h.I-LP-CEUR-AD.003.jpg In this particular example, I need to replace: h.I-LP-CEUR-AD.003.jpg with: I-LP-CEUR-AD.003.h.jpg Thank you for your responses! Capitalization counts. If the files are named with a .jpg, then your regexp pattern has to say .jpg. If the files are named with a .JPG, then your regexp pattern has to say .JPG. There is a flag that you can add at the end (were the g is) to do a case insensitive match, but not to do a case insensitive, but not to make the replacement string case insensitive. Add an i to the end of the statement: s/h\.(.*?)\.JPG/$1.h.JPG/gi; However, this will match files that start with a lowercase h as well as an uppercase H. If that's fine, then this regex will do the job. FL ___ vox-tech mailing list [EMAIL PROTECTED] http://lists.lugod.org/mailman/listinfo/vox-tech
Re: [vox-tech] Using awk or perl to find and replace
On Nov 24, 2004, at 9:56 AM, Foo Lim wrote: Add an i to the end of the statement: s/h\.(.*?)\.JPG/$1.h.JPG/gi; However, this will match files that start with a lowercase h as well as an uppercase H. If that's fine, then this regex will do the job. No... the problem is that it will take h.foo1.jpg and replace it with foo1.h.JPG Which probably won't work (since the case of the extension changes and most *nix are case sensitive...) The regex should be s/h\.(.*?)\.(JPG|jpg)/$1.h.$2/g; Or even more generally: s/h\.(.*?)\.([Jj][Pp][Gg])/$1.h.$2/g; Which you can wrap up in a single command like so perl -pi.orig -e 's/h.(.*?).([Jj][Pp][Gg])/$1.h.$2/g;' *.html which will do the replacement on all HTML files.. saving the originals with the extension .orig in case something goes horribly wrong and your need to undo it. -- Mitch ___ vox-tech mailing list [EMAIL PROTECTED] http://lists.lugod.org/mailman/listinfo/vox-tech
Re: [vox-tech] Understanding a C hello world program
Peter Jay Salzman wrote: Consider this program: snip [EMAIL PROTECTED] size hello_world-1.o textdata bss dec hex filename 48 0 0 48 30 hello_world-1.o When I disassemble the object file, I get 35 bytes: snip [EMAIL PROTECTED] objdump -h hello_world-1.o snip I wish objdump identified hex numbers as hex numbers. In any event, the text section has length x23, which is 35. The opcodes plus the string. Further evidence that the string lives in the text segment. Actually, objdump agrees with disassembly- string doesn't live in text region (35 bytes in both). Maybe my immediate question is -- where do read-only strings live? In the text section or the .rodata section? I've seen evidence that it lives in both section. Maybe gcc -S would be enlightening? It doesn't enlighten me, but then I don't know what a lot of the directives do (.section, for one). There is no .data directive, however, and the hello world\n definitely comes before the .text directive. It looks like: --- .section .rodata .LC0: .string hello world\n .text --- Maybe size, which doesn't seem to recognize .rodata, just lumps .data and everything else? -Bryan -- Bryan Richter UCDTT President UC Davis Undergrad, Physics Dept. - A PGP signature is (probably) attached to this email. signature.asc Description: Digital signature ___ vox-tech mailing list [EMAIL PROTECTED] http://lists.lugod.org/mailman/listinfo/vox-tech
Re: [vox-tech] Using awk or perl to find and replace
On Nov 24, 2004, at 10:15 AM, Mitch Patenaude wrote: perl -pi.orig -e 's/h.(.*?).([Jj][Pp][Gg])/$1.h.$2/g;' *.html oops.. that should be perl -pi.orig -e 's/h\.(.*?)\.([Jj][Pp][Gg])/$1.h.$2/g;' *.html (forgot to escape the literal periods. This is why my mom detests regex... it ends up looking an awful lot like old serial line noise. ;-) -- Mitch ___ vox-tech mailing list [EMAIL PROTECTED] http://lists.lugod.org/mailman/listinfo/vox-tech
Re: [vox-tech] Using awk or perl to find and replace
On Wed 24 Nov 04, 10:20 AM, Mitch Patenaude [EMAIL PROTECTED] said: On Nov 24, 2004, at 10:15 AM, Mitch Patenaude wrote: perl -pi.orig -e 's/h.(.*?).([Jj][Pp][Gg])/$1.h.$2/g;' *.html oops.. that should be perl -pi.orig -e 's/h\.(.*?)\.([Jj][Pp][Gg])/$1.h.$2/g;' *.html (forgot to escape the literal periods. This is why my mom detests regex... it ends up looking an awful lot like old serial line noise. ;-) -- Mitch LOL. That deserves to be in someone's .sig... ;-) Pete ___ vox-tech mailing list [EMAIL PROTECTED] http://lists.lugod.org/mailman/listinfo/vox-tech
Re: [vox-tech] Using awk or perl to find and replace
Not to beat a dead horse: perl -i.bak -p -e s/(h)\.(.*?)\.(jpg)/$2.$1.$3/ig input.txt In a perl one liner, making a backup of original, and saving capitalization ___ vox-tech mailing list [EMAIL PROTECTED] http://lists.lugod.org/mailman/listinfo/vox-tech
Re: [vox-tech] Using awk or perl to find and replace
On Wed, 24 Nov 2004, Mitch Patenaude wrote: On Nov 24, 2004, at 10:15 AM, Mitch Patenaude wrote: perl -pi.orig -e 's/h.(.*?).([Jj][Pp][Gg])/$1.h.$2/g;' *.html oops.. that should be perl -pi.orig -e 's/h\.(.*?)\.([Jj][Pp][Gg])/$1.h.$2/g;' *.html (forgot to escape the literal periods. This is why my mom detests regex... it ends up looking an awful lot like old serial line noise. ;-) Good catch(es). I stand corrected. :-) FL ___ vox-tech mailing list [EMAIL PROTECTED] http://lists.lugod.org/mailman/listinfo/vox-tech
Re: [vox-tech] yet another SQL question...[solved]
On Monday 22 November 2004 07:06 pm, David Hummel wrote: On Mon, Nov 22, 2004 at 02:00:59PM -0800, Dylan Beaudette wrote: I would like to make a table that displays the dominant component (i.e. comppct_r is the largest for a given larger unit) and associated attributes for each larger unit. I would use CREATE TABLE ... SELECT. I think the following SELECT will work: select mukey, max(comppct_r), taxorder, taxsuborder, taxgrtgroup from component group by mukey; -David (Feels like an idiot) Thanks, -- Dylan Beaudette Soil Science Graduate Group University of California at Davis ___ vox-tech mailing list [EMAIL PROTECTED] http://lists.lugod.org/mailman/listinfo/vox-tech
Re: [vox-tech] Understanding a C hello world program
On Wed, 24 Nov 2004, Peter Jay Salzman wrote:
[snip]
[EMAIL PROTECTED] size hello_world-1.o
textdata bss dec hex filename
48 0 0 48 30 hello_world-1.o
[snip]
What the... how did you make your program so small? My output:
$gcc hello.c -o hello
$size hello
textdata bss dec hex filename
960 256 41220 4c4 hello
$strip hello
$size hello
textdata bss dec hex filename
960 256 41220 4c4 hello
$ls -l hello
-rwxr-xr-x 1 markmark2948 Nov 24 10:24 hello*
$gcc --version
gcc (GCC) 3.3.5 (Debian 1:3.3.5-2)
[snip]
-_-'
I assume that data is the initialized data segment where programmer
initialized variables are stored. That's zero because I have no global
variables.
Yes.
I also assume that bss is zero because I have no programmer-uninitialized
global variables.
What is bss? Is that space dynamically generated in memory at runtime?
When I disassemble the object file, I get 35 bytes:
[snip]
however, size reports a text size of 48. Where do the extra 13 bytes come
from that size reports? Probably from hello world\n\0, which is 13 bytes.
Yes.
But if that's true, the string lives in the text segment. I always pictured
the text segment as being straight opcodes. There must be a structure to the
text segment that I was unaware of.
To the CPU, there's no distinction between opcodes and read-only data.
Pretty much the only differences between text and data sections are:
Text: r-x (readable, not writable, executable)
Data: rw- (readable, writable, not executable)
At least in theory. data section is also executable in practice which
allows buffer overflow to be used to execute malicious codes. But we
can't simply block out execution of the data section because I think
function pointers need to be executed outside the text area..???
Anyway, so if you think about a constant string like, hello, world,
there's no reason not to store it in the text section, because the string
isn't supposed to be changeable. If you were to store it in the data
section, however, you could accidentally overwrite it, which is fine from
a single-program point of view, but you can save some memory if you put it
in the text section, because the text section isn't replicated (only the
other sections) if you run multiple versions of the same program. This
makes it more important that the text section be non-writable and that
policy be enforced, so that one program accidentally modifying the text
section doesn't affect another instance of the same program.
Or that's how I understand it.
But then, looking at the output of the picture that objdump has of the object
file...
[snip]
However, I note that there's a section called .rodata, which I've never heard
of before, but I'm assumming that it stands for read only data section.
It's 13 bytes - just the size of hello world\n\0.
Looking at the assembly output (thanks for that idea, Bryan!), .rodata is
a custom name of a section:
.section .rodata
whereas the .text section is reserved:
.text
They might as well have named .rodata section as .whatever instead of
.rodata and it'll still work the same way. What the compiler does with
this section is I think linker-dependent, but it probably takes the
section and stick it in one of the canonical sections -- .text, .data,
etc. according to some predefined rule. (It's probably .text section by
default, unless specified otherwise.)
These custom sections are useful because it allows the linker to shuffle
them around to fit any hardware constraints that may exist. The linker
won't break up a section, though.
From the assembly output, the .rodata section goes before the .text
section, so it probably gets mapped to some default section which happens
to be .text. It's possible gcc knows to map the custom section named
.rodata to the .text area, but I just tried changing the name from .rodata
to .whatever and it still compiles without complaining.
That's probably why this
program segfaults:
#includestdio.h
int main(void)
{
char *string=hello world\n;
string[3] = 'T';
puts(string);
return 0;
}
because string is the address of something that lives in a section of memory
marked read-only. Whammo -- sigsegv. I remember Mark posting about 3 or 4
years ago that this actually worked on some other Unicies (not Linux).
Wow... you still remember that? Yeah I seem to recall trying out
something like that. I think it was one of Sun's OSes. Might have been
HP/UX, too, since those two were the primary other unices I had access to.
Maybe my immediate question is -- where do read-only strings live? In the
text section or the .rodata section? I've seen evidence that it lives in
both section.
.rodata is a custom section name which lives in the .text section. Think
of it as an alias to an offset
Re: [vox-tech] Understanding a C hello world program
On Wed, Nov 24, 2004 at 11:10:34AM -0800, Mark K. Kim wrote: On Wed, 24 Nov 2004, Peter Jay Salzman wrote: [snip] [EMAIL PROTECTED] size hello_world-1.o textdata bss dec hex filename 48 0 0 48 30 hello_world-1.o [snip] What the... how did you make your program so small? My output: $gcc hello.c -o hello $size hello textdata bss dec hex filename 960 256 41220 4c4 hello $strip hello $size hello textdata bss dec hex filename 960 256 41220 4c4 hello $ls -l hello -rwxr-xr-x 1 markmark2948 Nov 24 10:24 hello* $gcc --version gcc (GCC) 3.3.5 (Debian 1:3.3.5-2) [snip] -_-' He's working with hello.o, the output of gcc -c hello.c You're working with hello, the output of gcc -o hello hello.c So yours is a completely linked version of the file, and his is the object file pre-linking. He could use ld -o hello $LIBARIES hello.o to get what you have. --Ken Bloom -- I usually have a GPG digital signature included as an attachment. See http://www.gnupg.org/ for info about these digital signatures. signature.asc Description: Digital signature ___ vox-tech mailing list [EMAIL PROTECTED] http://lists.lugod.org/mailman/listinfo/vox-tech
Re: [vox-tech] Using awk or perl to find and replace
On Wednesday 24 November 2004 10:20, Mitch Patenaude wrote: On Nov 24, 2004, at 10:15 AM, Mitch Patenaude wrote: perl -pi.orig -e 's/h.(.*?).([Jj][Pp][Gg])/$1.h.$2/g;' *.html oops.. that should be perl -pi.orig -e 's/h\.(.*?)\.([Jj][Pp][Gg])/$1.h.$2/g;' *.html Absolutely perfect! Thanks! (forgot to escape the literal periods. This is why my mom detests regex... it ends up looking an awful lot like old serial line noise. ;-) -- Mitch ___ vox-tech mailing list [EMAIL PROTECTED] http://lists.lugod.org/mailman/listinfo/vox-tech ___ vox-tech mailing list [EMAIL PROTECTED] http://lists.lugod.org/mailman/listinfo/vox-tech
Re: [vox-tech] Understanding a C hello world program
On Wed 24 Nov 04, 11:10 AM, Mark K. Kim lugodatcbreakdotorg said:
On Wed, 24 Nov 2004, Peter Jay Salzman wrote:
[snip]
[EMAIL PROTECTED] size hello_world-1.o
textdata bss dec hex filename
48 0 0 48 30 hello_world-1.o
[snip]
What the... how did you make your program so small? My output:
Heh. I was working with the object file. No linking was done. :)
What is bss? Is that space dynamically generated in memory at runtime?
Yeah -- my understanding is that the data segment is divided into two parts:
a segment which gets initialized by the programmer and a segment that gets
initialized by the C library at run time. The latter is called bss, which
was a command used by an old assembler. It stood for block started by
symbol.
At least in theory. data section is also executable in practice which
allows buffer overflow to be used to execute malicious codes. But we
can't simply block out execution of the data section because I think
function pointers need to be executed outside the text area..???
Is that true? I'd think that function pointers necessarily need to point
inside the text section.
Anyway, so if you think about a constant string like, hello, world,
there's no reason not to store it in the text section, because the string
isn't supposed to be changeable. If you were to store it in the data
section, however, you could accidentally overwrite it, which is fine from
a single-program point of view, but you can save some memory if you put it
in the text section, because the text section isn't replicated (only the
other sections) if you run multiple versions of the same program. This
makes it more important that the text section be non-writable and that
policy be enforced, so that one program accidentally modifying the text
section doesn't affect another instance of the same program.
Or that's how I understand it.
No -- that makes perfect sense. I think that has to be true. Good thinking!
However, I note that there's a section called .rodata, which I've never
heard of before, but I'm assumming that it stands for read only data
section. It's 13 bytes - just the size of hello world\n\0.
Looking at the assembly output (thanks for that idea, Bryan!), .rodata is a
custom name of a section:
.section .rodata
whereas the .text section is reserved:
.text
They might as well have named .rodata section as .whatever instead of
.rodata and it'll still work the same way. What the compiler does with
this section is I think linker-dependent, but it probably takes the section
and stick it in one of the canonical sections -- .text, .data, etc.
according to some predefined rule. (It's probably .text section by
default, unless specified otherwise.)
More coolness.
These custom sections are useful because it allows the linker to shuffle
them around to fit any hardware constraints that may exist. The linker
won't break up a section, though.
YMC. Where did you learn this from? Have you taken a compiler class? At
some point in my life, I'd like to learn more about this.
That's probably why this program segfaults:
#includestdio.h
int main(void)
{
char *string=hello world\n;
string[3] = 'T';
puts(string);
return 0;
}
because string is the address of something that lives in a section of memory
marked read-only. Whammo -- sigsegv. I remember Mark posting about 3 or 4
years ago that this actually worked on some other Unicies (not Linux).
Wow... you still remember that? Yeah I seem to recall trying out
something like that. I think it was one of Sun's OSes. Might have been
HP/UX, too, since those two were the primary other unices I had access to.
Heh. I have just about every post you ever made to vox-tech saved on my hard
drive. ;-) I have subject folders and people folders. Some people
can't help but say interesting stuff.
Maybe my immediate question is -- where do read-only strings live? In the
text section or the .rodata section? I've seen evidence that it lives in
both section.
.rodata is a custom section name which lives in the .text section. Think
of it as an alias to an offset into the .text section. At least that's
how it worked in one assembler I used to use, and this seems to work the
same way from what you've discovered. That's pretty cool!
If anyone cares to riff off this, I'd certainly be interested in anything
anyone says.
I think it's cool that you've done all this analysis. I didn't know about
the size program and I haven't really seen much usage of objdump so it's
cool to see it used here. Thanks Peter!
I just asked the questions... you and Bryan answered them! :)
So just to reiterate. It appears that read-only strings get placed into a
custom section called .rodata by the compiler. Then, .rodata gets placed
into the .text segment during linking.
I've
[vox-tech] OT: are there any bigloo or objective CAML users?
Has anyone used Bigloo (a compiled scheme dialect) or objecgive CAML? -- Henry House Please don't send me HTML mail! My mail system will reject it. The unintelligible text that may follow is a digital signature. See http://hajhouse.org/pgp to find out how to use it. My OpenPGP key: http://hajhouse.org/hajhouse.asc. signature.asc Description: Digital signature ___ vox-tech mailing list [EMAIL PROTECTED] http://lists.lugod.org/mailman/listinfo/vox-tech
