STRSTR(3P)

📦 version 2017a, in alpine 3.22, alpine 3.23, alpine 3.24, arch rolling, nixpkgs unstable, opensuse-leap 16.0

💖 hey bestie, welcome to STRSTR(3P) 💖

okay so this is the POSIX Programmer's Manual page for strstr, and it lives in the 3P section of the manual. Yes, the P is for POSIX, we love a labeled queen. ✨

🚨 PROLOG 🚨

real talk for a sec: this manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ — so if you're on Linux, go consult the corresponding Linux manual page for the deets on Linux behavior. Or, plot twist, the interface may not be implemented on Linux at all. 😭 Check before you commit, bestie.

👑 NAME 👑

strstr — find a substring. that's it. that's the whole job. find the substring. 🎀

✨ SYNOPSIS ✨

#include <string.h>

char *strstr(const char *s1, const char *s2);

the way that signature just sits there being iconic. 💅

🌸 DESCRIPTION 🌸

Okay so, first thing: the functionality described on this reference page is aligned with the ISO C standard. If there's any conflict between what's written here and the ISO C standard — that's unintentional, fr fr. This volume of POSIX.1‐2017 defers to the ISO C standard. periodt. 👑

Now the actual tea: strstr() shall locate the first occurrence in the string pointed to by s1 of the sequence of bytes in the string pointed to by s2. And bestie, listen — that sequence of bytes excludes the terminating NUL character. Not the NUL. Never the NUL. 🙈

So like, s1 is the haystack, s2 is the needle, and we're finding needle #1. 🪡

🫶 RETURN VALUE 🫶

Upon successful completion, strstr() shall return a pointer to the located string, or a null pointer if the string is not found. 😭 no substring for you, babe.

And here's the cute little edge case that everyone forgets: if s2 points to a string with zero length, the function shall return s1. Yes really. Empty needle? You get the whole haystack pointer back. slay. 💖

💀 ERRORS 💀

No errors are defined. not one. zero. the error budget is empty, we spent it all on vibes. ✨

Heads up though: the following sections are informative. So like, they're the commentary track, not the actual rules. 🎀

🌈 EXAMPLES 🌈

None. 🙈 no examples today, we're keeping it mysterious.

🦋 APPLICATION USAGE 🦋

None. nope, nothing here either. moving on! 💅

⭐ RATIONALE ⭐

None. the reasoning is lost to time, bestie. or maybe there was never any reasoning. main character energy. 👑

🔥 FUTURE DIRECTIONS 🔥

None. the future is wide open and apparently undocumented. 🧚

👀 SEE ALSO 👀

  • strchr() — the sibling, the cousin, the other search function, go say hi 💜
  • The Base Definitions volume of POSIX.1‐2017, <string.h> — the header that makes it all possible, the blueprint, the source material 📜

Okay so legal moment, bear with me, it's giving paperwork but it matters:

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .

and that's the whole page, bestie!! 💖✨🎀

this lil masterpiece came to you courtesy of IEEE/The Open Group, dated 2017, and yeah the whole thing is filed under STRSTR(3P). go forth and find your substrings. 🦋🌸💅 no cap. 🫶

📦 where this page comes from