So, storing it as a char causes the segmentation fault. Stocking some data at the wrong position. Storing this string or character chain as a single char is trying to fit a square peg in a round hole.
A more day-to-day practical way of understanding this is, Segm. Fault is the same as trying to breath in water, your lungs were not made for that. Reserving memory for an integer and then trying to operate is as float or a string won't simply work.
Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Ask Question. Asked 11 years, 8 months ago. Active 2 months ago. Viewed k times. Improve this question. Jonathan Leffler k gold badges silver badges bronze badges. Rajendra Uppal Rajendra Uppal Just a memory dump when something goes wrong! Typically called by attempting to dereference a null pointer, so a segmentation fault is often analogous to a Java NullPointerException.
Segmentation comes from Memory Segmentation. You're accessing a segment of memory that does not belong to you. Add a comment. Active Oldest Votes. Improve this answer. Community Bot 1 1 1 silver badge. No warnings on compile. No segfault. The code can run fine on a production system for years, you alter another part of the code, change compiler or something else and BOOOOOM! Sorry for the bump but just a side note Not least because there are systems out there that operate without memory protection, thus cannot tell whether a piece of memory actually "belongs to you", and thus don't know segfaults, only undefined behaviour ChrisHuang-Leaver, normally when you get out of scope, the compiler has to recover some stack space to free the unused stack space, but this doesn't happen always with gcc being one of this compilers.
Also, the allocated stack space is normally reused again, so I have heard of no operating systems that return unused stack pages to the system, making that space subject for a SIGSEGV , so I won't expect such a signal from mangling with the stack. Show 4 more comments. And all of this with respect to virtual memory systems.
This is what I had on mind in "And things like shmat ; - these are what I count as 'indirect' access. In a virtual memory operating system there's no way normally, so please, operating system implementors, don't flame me for this for a process to access another process virtual memory, not being some kind of memory attach system call that allows you to access.
Virtual memory addresses normally mean different things depending on the process being considered. Ignacio Vazquez-Abrams Ignacio Vazquez-Abrams k gold badges silver badges bronze badges. These kinds of errors are usually caused by pointers that are Used before being properly initialised Used after the memory they point to has been realloced or deleted.
Used in an indexed array where the index is outside of the array bounds. Component 10 Component 10 9, 5 5 gold badges 43 43 silver badges 59 59 bronze badges. According to Wikipedia : A segmentation fault occurs when a program attempts to access a memory location that it is not allowed to access, or attempts to access a memory location in a way that is not allowed for example, attempting to write to a read-only location, or to overwrite part of the operating system.
Fabio says Reinstate Monica 4, 7 7 gold badges 38 38 silver badges 52 52 bronze badges. Orhan Cinar Orhan Cinar 8, 2 2 gold badges 34 34 silver badges 48 48 bronze badges. Start your debugger with the command gdb core , and then use the backtrace command to see where the program was when it crashed. This simple trick will allow you to focus on that part of the code. If using backtrace on the core g file doesn't find the problem, you might have to run the program under debugger control, and then step through the code one function, or one source code line, at a time.
To do this, you will need to compile your code without optimization, and with the -g flag, so information about source code lines will be embedded in the executable file. This is document aqsj in the Knowledge Base. Last modified on Skip to: content search login. Knowledge Base Toggle local menu Menus About the team. Knowledge Base Search.
Log in. Options Help Chat with a consultant. Refer Storage for Strings in C for details. Improper use of scanf : scanf function expects address of a variable as an input. If we pass n to scanf , input fetched from STDIN is placed in invalid memory 2 which should be instead. Running out of memory on the stack is also a type of memory corruption. It can be resolved by having a base condition to return from the recursive function.
Dereferencing uninitialized pointer A pointer must point to valid memory before accessing it. If you like GeeksforGeeks and would like to contribute, you can also write an article using write. See your article appearing on the GeeksforGeeks main page and help other Geeks. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above. Skip to content.
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