One assignment I give students in my "Advanced Programming in the UNIX Environment" class includes reading data from a pipe into a fixed-size buffer.
A clever approach for that is
```
total = 0;
while ((n = read(fd, buf + total, len - total)) > 0)
total += n;
```
This is a common construct found (but not explained) in StackOverflow posts and different open source code bases. But it's not something students tend to come up with on their own and struggle to explain if asked.
Jan Schaumann
npub1kv…medh2
2025-11-18 16:24:37 UTC
Author Public Key
npub1kvy8enal7npw9ct28tc53d4r5fl7q7a3ua3gku22z8jlyec37f3snmedh2Seen on
wss://relay.ditto.pubPublished at
2025-11-18 16:24:37 UTCEvent JSON
{
"id": "b5972c3db63ab5c9a5b40c2d0f8f12d1146dcc432ba9834852dd88c7cf2b059f",
"pubkey": "b3087ccfbff4c2e2e16a3af148b6a3a27fe07bb1e7628b714a11e5f26711f263",
"created_at": 1763483077,
"kind": 1,
"tags": [
[
"proxy",
"https://mstdn.social/users/jschauma/statuses/115571626940691255",
"activitypub"
],
[
"client",
"Mostr",
"31990:6be38f8c63df7dbf84db7ec4a6e6fbbd8d19dca3b980efad18585c46f04b26f9:mostr",
"wss://relay.ditto.pub/"
]
],
"content": "One assignment I give students in my \"Advanced Programming in the UNIX Environment\" class includes reading data from a pipe into a fixed-size buffer.\n\nA clever approach for that is\n\n```\ntotal = 0;\nwhile ((n = read(fd, buf + total, len - total)) \u003e 0)\n total += n;\n```\n\nThis is a common construct found (but not explained) in StackOverflow posts and different open source code bases. But it's not something students tend to come up with on their own and struggle to explain if asked.",
"sig": "da1f4a5903d8f25fec4dc516254f6b5edd08222e468fde19bf0d869a7f5df3cc96ee36b4ff51a81c4ee6cb14c06fb4befec4a56aa0a83b77226aa697721748be"
}