Javier Martín-Torres is a Spanish astrophysicist and researcher known for his work in planetary science, particularly in the study of Mars and the potential for life in extraterrestrial environments. He has been involved in research related to the atmospheric conditions on Mars, the habitability of other celestial bodies, and the implications of his findings for understanding the potential for life beyond Earth.
hello_world_len points to the special st_shndx == SHN_ABS == 0xF1FF.0xF1FF is chosen so as to not conflict with other sections.st_value == 0xD == 13 which is the value we have stored there on the assembly: the length of the string Hello World!.This is small optimization that our assembler does for us and which has ELF support.
Section type:
sh_type == SHT_STRTAB.Common name: "section header string table".
This section gets pointed to by the
e_shstrnd field of the ELF header itself.String indexes of this section are are pointed to by the
sh_name field of section headers, which denote strings.This section does not have outputs:
SHF_ALLOC marked, so it will not appear on the executing program.readelf -x .shstrtab hello_world.oHex dump of section '.shstrtab':
0x00000000 002e6461 7461002e 74657874 002e7368 ..data..text..sh
0x00000010 73747274 6162002e 73796d74 6162002e strtab..symtab..
0x00000020 73747274 6162002e 72656c61 2e746578 strtab..rela.tex
0x00000030 7400 t.In index 0,
SHT_NULL is mandatory. Are there any other uses for it: stackoverflow.com/questions/26812142/what-is-the-use-of-the-sht-null-section-in-elf ?Richard A. Anthes is a prominent figure in the fields of meteorology and atmospheric science. He is best known for his contributions to weather forecasting and climate research, particularly through his work with the National Center for Atmospheric Research (NCAR) in the United States, where he served as director from 1988 to 1999. Anthes has been influential in the development of numerical weather prediction models and has made significant contributions to understanding mesoscale meteorology and the interaction between weather and climate.
ELF Hello World Tutorial 
Ciro Santilli 37 Updated 2025-07-01 +Created 1970-01-01
SHT_STRTAB by Ciro Santilli 37 Updated 2025-07-01 +Created 1970-01-01Sections with
sh_type == SHT_STRTAB are called string tables.They hold a null separated array of strings.
Such sections are used by other sections when string names are to be used. The using section says:
- which string table they are using
- what is the index on the target string table where the string starts
So for example, we could have a string table containing:
Data: \0 a b c \0 d e f \0
Index: 0 1 2 3 4 5 6 7 8And if another section wants to use the string
d e f, they have to point to index 5 of this section (letter d).Notable string table sections:
.shstrtab.strtab
ELF Hello World Tutorial Ciro Santilli 37 Updated 2025-07-01 +Created 1970-01-01
SHT_SYMTAB on the executable by Ciro Santilli 37 Updated 2025-07-01 +Created 1970-01-01Atmospheric sounding is a technique used to measure and analyze the vertical profile of atmospheric variables, such as temperature, humidity, and pressure, throughout the atmosphere. This process provides critical data that helps meteorologists and scientists understand weather patterns, climate variations, and atmospheric conditions. There are several methods and instruments used for atmospheric sounding, including: 1. **Weather Balloons (Radiosondes)**: A common method involving the release of balloons that carry instruments (radiosondes) into the atmosphere.
Boundary layer meteorology is a specialized field of meteorology that focuses on the atmospheric boundary layer (ABL), which is the lowest part of the Earth's atmosphere. This region extends from the surface up to a few kilometers above ground level and is directly influenced by the Earth's surface and its characteristics, such as land use, vegetation, topography, and temperature.
High Integrity C++ is a set of guidelines and methodologies aimed at ensuring the reliability, safety, and maintainability of C++ code, particularly in critical systems where failures can lead to significant consequences, such as in aerospace, automotive, medical devices, and other safety-critical applications. The main focus of High Integrity C++ is to provide a standardized approach to developing software that adheres to strict quality standards.
ELF Hello World Tutorial Specified file formats by Ciro Santilli 37 Updated 2025-07-01 +Created 1970-01-01
Ciro Santilli 37 Updated 2025-07-01 +Created 1970-01-01The ELF standard specifies multiple file formats:
- Object files (
.o).Intermediate step to generating executables and other formats:Source code | | Compilation | v Object file | | Linking | v ExecutableObject files exist to make compilation faster: withmake, we only have to recompile the modified source files based on timestamps.
- Executable files (no standard Linux extension).This is what the Linux kernel can actually run.
- Archive files (
.a).Libraries meant to be embedded into executables during the Linking step.
- Shared object files (
.so).Libraries meant to be loaded when the executable starts running.
- Core dumps.Such files may be generated by the Linux kernel when the program does naughty things, e.g. segfault.They exist to help debugging the program.
In this tutorial, we consider only object and executable files.
Cloud and fog physics is a branch of atmospheric science that focuses on understanding the formation, development, and interactions of clouds and fog in the Earth's atmosphere. This field of study encompasses various processes related to the microphysical, thermodynamic, and dynamic properties of clouds and fog. ### Key Components of Cloud and Fog Physics: 1. **Cloud Formation**: Clouds form when moist air rises, cools, and condenses into water droplets or ice crystals.
Atom localization generally refers to the methods and processes used to determine the precise position of atoms within a given system or material. The concept is particularly relevant in various fields such as physics, chemistry, and material science. In the context of quantum mechanics and condensed matter physics, atom localization can describe scenarios where atoms or particles are influenced by potential wells or barriers that restrict their movement, leading to localized states.
ELF is specified by the LSB:
The LSB basically links to other standards with minor extensions, in particular:
- Generic (both by SCO):
- System V ABI 4.1 (1997) www.sco.com/developers/devspecs/gabi41.pdf, no 64 bit, although a magic number is reserved for it. Same for core files. This is the first document you should look at when searching for information.
- System V ABI Update DRAFT 17 (2003) www.sco.com/developers/gabi/2003-12-17/contents.html, adds 64 bit. Only updates chapters 4 and 5 of the previous document: the others remain valid and are still referenced.
- Architecture specific (by the processor vendor):
A handy summary can be found at:
man elfHolds strings for the symbol table.
This section has
sh_type == SHT_STRTAB.It is pointed to by outputs:
sh_link == 5 of the .symtab section.readelf -x .strtab hello_world.oHex dump of section '.strtab':
0x00000000 0068656c 6c6f5f77 6f726c64 2e61736d .hello_world.asm
0x00000010 0068656c 6c6f5f77 6f726c64 0068656c .hello_world.hel
0x00000020 6c6f5f77 6f726c64 5f6c656e 005f7374 lo_world_len._st
0x00000030 61727400 art.This implies that it is an ELF level limitation that global variables cannot contain NUL characters.
Atomic electron transition refers to the process by which an electron in an atom moves from one energy level (or state) to another. This transition can occur when an electron absorbs or emits energy, typically in the form of photons (light quanta). The fundamental aspects of atomic electron transitions can be summarized as follows: 1. **Energy Levels**: Electrons exist in discrete energy levels or orbitals around the nucleus of an atom. Each level corresponds to a specific energy state.
An atomic orbital is a mathematical function that describes the wave-like behavior of an electron in an atom. This concept arises from quantum mechanics and is fundamental to understanding the structure of atoms and the arrangement of electrons within them. Here are some key points about atomic orbitals: 1. **Shape and Energy**: Atomic orbitals have distinct shapes (spherical, dumbbell-shaped, etc.) and energy levels. The shape and orientation of an orbital are determined by the quantum numbers that describe it.
Atomic recoil refers to the phenomenon that occurs when an atom or a nucleus absorbs energy from a photon (a particle of light) or a particle (such as an alpha or beta particle) during an interaction. When this energy is absorbed, the atom is set into motion due to the conservation of momentum, and it recoils as a reaction to the incoming energy. In a quantum context, when an atom absorbs a photon, it can be excited to a higher energy state.
- 10 8:
st_name=01000000= character 1 in the.strtab, which until the following\0makeshello_world.asmThis piece of information file may be used by the linker to decide on which segment sections go: e.g. inldlinker script we write:segment_name : { file(section) }segment_name : { *(section) } - 10 13:
st_shndx= Symbol Table Section header Index =f1ff=SHN_ABS. Required forSTT_FILE. - 20 0:
st_value= 8x00: required for value forSTT_FILE - 20 8:
st_size= 8x00: no allocated size
Now from the
readelf, we interpret the others quickly. Pinned article: ourbigbook/introduction-to-the-ourbigbook-project
Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
Intro to OurBigBook
. Source. We have two killer features:
- topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculusArticles of different users are sorted by upvote within each article page. This feature is a bit like:
- a Wikipedia where each user can have their own version of each article
- a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
Figure 1. Screenshot of the "Derivative" topic page. View it live at: ourbigbook.com/go/topic/derivativeVideo 2. OurBigBook Web topics demo. Source. - local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
Figure 2. You can publish local OurBigBook lightweight markup files to either OurBigBook.com or as a static website.
Figure 3. Visual Studio Code extension installation.
Figure 5. . You can also edit articles on the Web editor without installing anything locally. Video 3. Edit locally and publish demo. Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension. 
- Infinitely deep tables of contents:
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact