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SIGTRAP

Signals are standardized messages sent to a running program to trigger specific behavior, such as quitting or error handling.

Version
v1 · 2026-09-28 · History
Domain-specific #
12043
Domain group
Applied Sciences & Engineering
Origin domain
Computer Science & Software Engineering
Subdomains
Operating Systems, Posix Signals → Computer Science & Software Engineering

Core Idea

SIGTRAP is treated here as the recurring computer_science_and_information identity summarized by this source-grounded definition: Signals are standardized messages sent to a running program to trigger specific behavior, such as quitting or error handling.

Signals are standardized messages sent to a running program to trigger specific behavior, such as quitting or error handling. They are a limited form of inter-process communication (IPC), typically used in Unix, Unix-like, and other POSIX-compliant operating systems. A signal is an asynchronous notification sent to a process or to a specific thread within the same process to notify it of an event.

Common uses of signals are to interrupt, suspend, terminate or kill a process. Signals originated in 1970s Bell Labs Unix and were later specified in the POSIX standard. When a signal is sent, the operating system interrupts the target process's normal flow of execution to deliver the signal.

For SIGTRAP, the abstraction is narrower than the article's general subject matter: a positive case must preserve Signals are standardized messages sent to a running program to trigger specific behavior, such as quitting or error handling. Retaining only the name, a familiar example, or a downstream effect is insufficient. The specialist roles and tests remain anchored in computer_science_and_information, which is why this identity is domain-specific rather than prime.

Structural Signature

Sig role-phrases:

  • Defining carrier — For example, #SIGPIPE| will be generated when a process writes to a pipe which has been closed by the reader; by default, this causes the process to terminate, which is convenient when constructing shell pipelines.
  • Constitutive relation — Ctrl-C (in older Unixes, DEL) sends an signal ("interrupt", #SIGINT|); by default, this causes the process to terminate.
  • Operating condition — Ctrl-Z sends a signal ("terminal stop", SIGTSTP|); by default, this causes the process to suspend execution.
  • Recognition evidence — Ctrl- sends a signal (#SIGQUIT|); by default, this causes the process to terminate and dump core.
  • Admissible variation — Typing certain key combinations at the controlling terminal of a running process causes the system to send it certain signals.
  • Characteristic consequence — Ctrl-T (not supported on all UNIXes) sends an signal (#SIGINFO|); by default, and if supported by the command, this causes the operating system to show information about the running command.
  • Failure boundary — Signals should be processed from the queue on the main thread and not by worker pools, as that reintroduces the problem of asynchronicity.

What It Is Not

  • Not the whole field of computer_science_and_information. The node requires the specific identity stated by Signals are standardized messages sent to a running program to trigger specific behavior, such as quitting or error handling.
  • Not an over-broad reading. However, managing a queue is not possible in an async-signal safe way with only , as only single reads and writes to such variables are guaranteed to be atomic, not increments or (fetch-and)-decrements, as would be required for a queue.
  • Not an over-broad reading. For other exceptions, however, the kernel cannot process them intelligently and it must defer the exception handling operation to the faulting process.
  • Not an over-broad reading. The signal is sent to a process when an exceptional (but not necessarily erroneous) condition has been detected in the floating-point or integer arithmetic hardware.
  • Not automatically sigaction. Retrieval proximity does not establish equivalence; the two identities must be compared by carrier, operation, and failure boundary.

Scope of Application

SIGTRAP applies literally inside computer_science_and_information wherever the source-defined carrier and relation can be established. Its documented habitats include:

  • POSIX signals. The term reflects early usage of such instructions, predominantly to implement I/O functions, but they are not inherently tied to device I/O and may be used for other purposes such as communication between virtual & real hosts.
  • POSIX signals. In practice, this kind of signal is rarely encountered since applications rely on libraries (e.g. libc) to make the call for them. can be received by applications violating the Linux Seccomp security rules configured to restrict them. can also be used to emulate foreign system calls, e.g. emulate Windows system calls on Linux.
  • POSIX signals. On some systems may be used internally by the implementation of the sleep function.
  • POSIX signals. The to signals are intended to be used for user-defined purposes.
  • Handling signals. If a signal handler is not installed for a particular signal, the default handler is used.
  • Risks. The call can be used to block and unblock delivery of signals.

Outside computer_science_and_information, the name should be retained only when these same operational conditions survive; otherwise the comparison belongs to the broader parent Pattern or should be marked as analogy.

Clarity

A clear use of SIGTRAP names the carrier, the operative relation, and the conditions under which the source treats the identity as present. The minimal definition is Signals are standardized messages sent to a running program to trigger specific behavior, such as quitting or error handling. The strongest recognition evidence in the frozen account is: Ctrl- sends a signal (#SIGQUIT|); by default, this causes the process to terminate and dump core. A report should distinguish that evidence from a proxy, consequence, or common implementation. It should also state the qualification However, managing a queue is not possible in an async-signal safe way with only , as only single reads and writes to such variables are guaranteed to be atomic, not increments or (fetch-and)-decrements, as would be required for a queue. so that a reader can reproduce the classification rather than infer it from topical resemblance.

Manages Complexity

SIGTRAP compresses multiple computer_science_and_information details into a stable diagnostic relation. The source shows both the central mechanism—ctrl-C (in older Unixes, DEL) sends an signal ("interrupt", #SIGINT|); by default, this causes the process to terminate.—and the practical consequence—ctrl-T (not supported on all UNIXes) sends an signal (#SIGINFO|); by default, and if supported by the command, this causes the operating system to show information about the running command. This compression makes cases comparable while leaving parameters, conventions, exceptions, and evidential quality explicit. It is lossy by design: local history and implementation details may be omitted only when they do not alter the defining relation.

Abstract Reasoning

  1. Type the carrier. Identify the computer_science_and_information entities to which the claim applies.
  2. State the relation. Use the source-grounded identity: Signals are standardized messages sent to a running program to trigger specific behavior, such as quitting or error handling.
  3. Check operation and conditions. Ctrl-Z sends a signal ("terminal stop", SIGTSTP|); by default, this causes the process to suspend execution.
  4. Demand recognition evidence. Ctrl- sends a signal (#SIGQUIT|); by default, this causes the process to terminate and dump core.
  5. Test variation. Change an implementation or setting while preserving typing certain key combinations at the controlling terminal of a running process causes the system to send it certain signals.
  6. Run the collapse test. Remove the defining operation; if the label still seems equally apt, only a topic or correlate was retained.
  7. Reduce cautiously. When the specialist conditions cannot be carried, route the residual comparison to Pattern.

Knowledge Transfer

Within the home domain. Knowledge about SIGTRAP transfers literally when a new case preserves the same carrier type, relation, and recognition test. The term reflects early usage of such instructions, predominantly to implement I/O functions, but they are not inherently tied to device I/O and may be used for other purposes such as communication between virtual & real hosts. In practice, this kind of signal is rarely encountered since applications rely on libraries (e.g. libc) to make the call for them. can be received by applications violating the Linux Seccomp security rules configured to restrict them. can also be used to emulate foreign system calls, e.g. emulate Windows system calls on Linux.

Beyond the home domain. No canonical parent is asserted for SIGTRAP. An outside case receives the specialist name only when the same typed roles and rejection conditions can be filled literally; otherwise the comparison remains an analogy pending later graph densification.

Examples

Canonical

In case of some exceptions, such as a page fault, the kernel has sufficient information to fully handle the event itself and resume the process's execution. This case is canonical because it supplies a concrete carrier and lets the defining relation be checked rather than merely named.

Mapped back: carrier → the entities in the documented case; operation → Signals are standardized messages sent to a running program to trigger specific behavior, such as quitting or error handling; recognition evidence → Ctrl- sends a signal (#SIGQUIT|); by default, this causes the process to terminate and dump core

Applied / In Practice

Exceptions such as division by zero, segmentation violation (#SIGSEGV|), and floating point exception (#SIGFPE|) will cause a core dump and terminate the program. The applied case shows how the identity is used under a second setting or qualification while keeping the same operative relation.

Mapped back: changed setting → Sending signals; invariant → Signals are standardized messages sent to a running program to trigger specific behavior, such as quitting or error handling; boundary → the case exits the class when however, managing a queue is not possible in an async-signal safe way with only , as only single reads and writes to such variables are guaranteed to be atomic, not increments or (fetch-and)-decrements, as would be required for a queue

Structural Tensions

T1 — Stable identity versus admissible variation. However, managing a queue is not possible in an async-signal safe way with only , as only single reads and writes to such variables are guaranteed to be atomic, not increments or (fetch-and)-decrements, as would be required for a queue. The tension matters because emphasizing only one side either dissolves the identity or overstates what the evidence and domain conventions warrant.

Diagnostic: Which changes preserve the defining relation, and which replace it?

T2 — Recognition versus proxy. For other exceptions, however, the kernel cannot process them intelligently and it must defer the exception handling operation to the faulting process. The tension matters because emphasizing only one side either dissolves the identity or overstates what the evidence and domain conventions warrant.

Diagnostic: Does the cited evidence establish the identity or only a correlated sign?

T3 — Definition versus implementation. The signal is sent to a process when an exceptional (but not necessarily erroneous) condition has been detected in the floating-point or integer arithmetic hardware. The tension matters because emphasizing only one side either dissolves the identity or overstates what the evidence and domain conventions warrant.

Diagnostic: Is the observed implementation constitutive, optional, or merely common?

T4 — Scope versus overextension. Exceptions such as division by zero, segmentation violation (#SIGSEGV|), and floating point exception (#SIGFPE|) will cause a core dump and terminate the program. The tension matters because emphasizing only one side either dissolves the identity or overstates what the evidence and domain conventions warrant.

Diagnostic: Can every claimed application fill the same typed roles without metaphor?

T5 — Transfer versus domain accent. For example, #SIGPIPE| will be generated when a process writes to a pipe which has been closed by the reader; by default, this causes the process to terminate, which is convenient when constructing shell pipelines. The tension matters because emphasizing only one side either dissolves the identity or overstates what the evidence and domain conventions warrant.

Diagnostic: Does the receiving case instantiate SIGTRAP literally, co-instantiate Pattern, or only resemble it?

T6 — Autonomy versus reduction. Ctrl-C (in older Unixes, DEL) sends an signal ("interrupt", #SIGINT|); by default, this causes the process to terminate. The tension matters because emphasizing only one side either dissolves the identity or overstates what the evidence and domain conventions warrant.

Diagnostic: What does SIGTRAP distinguish that the broader parent Pattern leaves together?

Structural–Framed Character

SIGTRAP is structural-leaning. Its structural side is the repeatable organization summarized by Signals are standardized messages sent to a running program to trigger specific behavior, such as quitting or error handling. Its framed side is the computer_science_and_information vocabulary that fixes the carrier, evidence, exceptions, and admissible transformations.

Evaluative weight: the identity can be stated descriptively even when applications carry practical stakes. Human-practice dependence: the source-grounded carrier determines whether the relation exists independently or is constituted by a practice. Institutional origin: disciplinary conventions stabilize the name and test. Vocabulary portability: Ctrl-Z sends a signal ("terminal stop", SIGTSTP|); by default, this causes the process to suspend execution. Import versus recognition: literal transfer requires the same mechanism; shape alone is analogy.

Its portable skeleton is Pattern. Its character: a recurring specialist identity whose thin organization can be abstracted, while its operational meaning remains domain-bound.

Structural Core vs. Domain Accent

What is skeletal. Signals are standardized messages sent to a running program to trigger specific behavior, such as quitting or error handling. The stable skeleton is the typed relation expressed in that definition and the entry's recognition and collapse tests. The source identifies these operative conditions: For example, #SIGPIPE| will be generated when a process writes to a pipe which has been closed by the reader; by default, this causes the process to terminate, which is convenient when constructing shell pipelines. Ctrl-C (in older Unixes, DEL) sends an signal ("interrupt", #SIGINT|); by default, this causes the process to terminate. It further constrains recognition and variation through: Ctrl-Z sends a signal ("terminal stop", SIGTSTP|); by default, this causes the process to suspend execution. Ctrl- sends a signal (#SIGQUIT|); by default, this causes the process to terminate and dump core.

What is domain-bound. computer science and information supplies the operative entities, technical vocabulary, warrants, and exceptions that make SIGTRAP literal. Its documented scope includes the condition that The term reflects early usage of such instructions, predominantly to implement I/O functions, but they are not inherently tied to device I/O and may be used for other purposes such as communication between virtual & real hosts. Another bounded application condition is that In practice, this kind of signal is rarely encountered since applications rely on libraries (e.g. libc) to make the call for them. can be received by applications violating the Linux Seccomp security rules configured to restrict them. can also be used to emulate foreign system calls, e.g. emulate Windows system calls on Linux. These are not decorative examples; they determine which carrier and evidence can fill the abstraction's roles.

Why no parent is asserted. Removing those specialist details does not currently yield one live catalog node that is a necessary genus for every instance. The entry is therefore approved as unparented rather than attached by topical resemblance. Its collapse evidence remains specific—Typing certain key combinations at the controlling terminal of a running process causes the system to send it certain signals.—and future graph densification may discover a defensible relation only if it preserves that boundary.

  • Approved unparented node. No current live node supplies a defensible necessary genus or structural prerequisite for SIGTRAP. The reviewed identity is: Signals are standardized messages sent to a running program to trigger specific behavior, such as quitting or error handling. The accelerated suggestion was declined because topical or lexical similarity does not establish hierarchy; the node is admitted without a parent pending later graph densification.
  • Related reasoning operations. Evidence, representation, comparison, classification, transformation, or evaluation may participate in particular cases, but participation does not make any one of them a necessary parent of every instance.

Neighborhood in Abstraction Space

SIGTRAP sits in a sparse region of the domain-specific corpus (67th percentile for distinctiveness): few abstractions share its structure, so a faithful description tends to retrieve it precisely.

Family — Unclustered & Miscellaneous (2551 abstractions)

Nearest neighbors

Computed from structural-signature embeddings · 2026-10-08

Not to Be Confused With

  • Pattern. The parent omits the specialist differentia. Tell: Can the case establish Signals are standardized messages sent to a running program to trigger specific behavior, such as quitting or error handling?
  • sigaction. The POSIX interface for examining or replacing one signal's process-wide disposition together with its handler-time mask and behavioral flags, while optionally returning the prior action as a restorable state. Tell: Which entry's carrier, operation, and failure condition are satisfied?
  • Pragmatics. What a signal means in context is the joint product of its literal content and patterned contextual machinery, not just what the signal literally encodes. Tell: Which entry's carrier, operation, and failure condition are satisfied?
  • Signal Modulation. Signal modulation varies a property of a carrier waveform in accordance with an information-bearing message so the message can be transmitted, multiplexed, and later recovered by demodulation. Tell: Which entry's carrier, operation, and failure condition are satisfied?
  • A measurement, proxy, or consequence. Those may provide evidence without being the identity. Tell: Would SIGTRAP remain present if the detector or downstream effect changed?
  • A metaphorical analogue. A similar shape outside computer_science_and_information lacks the specialist mechanism. Tell: Do the native roles transfer literally, or only the parent Pattern?

References

  • Frozen Wikipedia discovery revision: https://en.wikipedia.org/wiki/Signal_(IPC) (revision 1357313893).
  • Preserved source candidate: https://www.cs.dartmouth.edu/~doug/reader.pdf
  • Preserved source candidate: https://doc.cat-v.org/plan_9/programming/c_programming_in_plan_9
  • Preserved source candidate: https://www.gnu.org/software/libc/manual/html_node/Termination-Signals.html
  • Preserved source candidate: https://www.gnu.org/software/libc/manual/html_node/Job-Control-Signals.html
  • Preserved source candidate: https://www.gnu.org/software/libc/manual/html_node/Miscellaneous-Signals.html
  • Preserved source candidate: https://pubs.opengroup.org/onlinepubs/009695399/functions/xsh_chap02_04.html#tag_02_04
  • Preserved source candidate: https://man7.org/linux/man-pages/man7/signal.7.html
  • Preserved source candidate: https://man7.org/linux/man-pages/man7/signal-safety.7.html

The frozen Wikipedia revision is discovery provenance. The retained source set was reviewed for identity, formal or operational relation, and scope. The encyclopedia's structural synthesis is bounded to those claims; a thin authority surface is recorded as a nonblocking source-strengthening repair rather than concealed.