##// END OF EJS Templates
posix: always seek to EOF when opening a file in append mode...
posix: always seek to EOF when opening a file in append mode Python 3 already does this, so skip it there. Consider the program: #include <stdio.h> int main() { FILE *f = fopen("narf", "w"); fprintf(f, "narf\n"); fclose(f); f = fopen("narf", "a"); printf("%ld\n", ftell(f)); fprintf(f, "troz\n"); printf("%ld\n", ftell(f)); return 0; } on macOS, FreeBSD, and Linux with glibc, this program prints 5 10 but on musl libc (Alpine Linux and probably others) this prints 0 10 By my reading of https://pubs.opengroup.org/onlinepubs/009695399/functions/fopen.html this is technically correct, specifically: > Opening a file with append mode (a as the first character in the > mode argument) shall cause all subsequent writes to the file to be > forced to the then current end-of-file, regardless of intervening > calls to fseek(). in other words, the file position doesn't really matter in append-mode files, and we can't depend on it being at all meaningful unless we perform a seek() before tell() after open(..., 'a'). Experimentally after a .write() we can do a .tell() and it'll always be reasonable, but I'm unclear from reading the specification if that's a smart thing to rely on. This matches what we do on Windows and what Python 3 does for free, so let's just be consistent. Thanks to Yuya for the idea.

File last commit:

r41000:98a0fbda default
r42778:97ada9b8 5.0.2 stable
Show More
Cargo.lock
136 lines | 6.0 KiB | text/plain | TextLexer
[[package]]
name = "aho-corasick"
version = "0.5.3"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"memchr 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
]
[[package]]
name = "cpython"
version = "0.1.0"
source = "git+https://github.com/indygreg/rust-cpython.git?rev=c90d65cf84abfffce7ef54476bbfed56017a2f52#c90d65cf84abfffce7ef54476bbfed56017a2f52"
dependencies = [
"libc 0.2.45 (registry+https://github.com/rust-lang/crates.io-index)",
"num-traits 0.1.43 (registry+https://github.com/rust-lang/crates.io-index)",
"python27-sys 0.1.2 (git+https://github.com/indygreg/rust-cpython.git?rev=c90d65cf84abfffce7ef54476bbfed56017a2f52)",
]
[[package]]
name = "hgcli"
version = "0.1.0"
dependencies = [
"cpython 0.1.0 (git+https://github.com/indygreg/rust-cpython.git?rev=c90d65cf84abfffce7ef54476bbfed56017a2f52)",
"libc 0.2.45 (registry+https://github.com/rust-lang/crates.io-index)",
"python27-sys 0.1.2 (git+https://github.com/indygreg/rust-cpython.git?rev=c90d65cf84abfffce7ef54476bbfed56017a2f52)",
]
[[package]]
name = "kernel32-sys"
version = "0.2.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
"winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
]
[[package]]
name = "libc"
version = "0.2.45"
source = "registry+https://github.com/rust-lang/crates.io-index"
[[package]]
name = "memchr"
version = "0.1.11"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"libc 0.2.45 (registry+https://github.com/rust-lang/crates.io-index)",
]
[[package]]
name = "num-traits"
version = "0.1.43"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"num-traits 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
]
[[package]]
name = "num-traits"
version = "0.2.6"
source = "registry+https://github.com/rust-lang/crates.io-index"
[[package]]
name = "python27-sys"
version = "0.1.2"
source = "git+https://github.com/indygreg/rust-cpython.git?rev=c90d65cf84abfffce7ef54476bbfed56017a2f52#c90d65cf84abfffce7ef54476bbfed56017a2f52"
dependencies = [
"libc 0.2.45 (registry+https://github.com/rust-lang/crates.io-index)",
"regex 0.1.80 (registry+https://github.com/rust-lang/crates.io-index)",
]
[[package]]
name = "regex"
version = "0.1.80"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"aho-corasick 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)",
"memchr 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
"regex-syntax 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
"thread_local 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
"utf8-ranges 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
]
[[package]]
name = "regex-syntax"
version = "0.3.9"
source = "registry+https://github.com/rust-lang/crates.io-index"
[[package]]
name = "thread-id"
version = "2.0.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
"libc 0.2.45 (registry+https://github.com/rust-lang/crates.io-index)",
]
[[package]]
name = "thread_local"
version = "0.2.7"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"thread-id 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
]
[[package]]
name = "utf8-ranges"
version = "0.1.3"
source = "registry+https://github.com/rust-lang/crates.io-index"
[[package]]
name = "winapi"
version = "0.2.8"
source = "registry+https://github.com/rust-lang/crates.io-index"
[[package]]
name = "winapi-build"
version = "0.1.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
[metadata]
"checksum aho-corasick 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)" = "ca972c2ea5f742bfce5687b9aef75506a764f61d37f8f649047846a9686ddb66"
"checksum cpython 0.1.0 (git+https://github.com/indygreg/rust-cpython.git?rev=c90d65cf84abfffce7ef54476bbfed56017a2f52)" = "<none>"
"checksum kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7507624b29483431c0ba2d82aece8ca6cdba9382bff4ddd0f7490560c056098d"
"checksum libc 0.2.45 (registry+https://github.com/rust-lang/crates.io-index)" = "2d2857ec59fadc0773853c664d2d18e7198e83883e7060b63c924cb077bd5c74"
"checksum memchr 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)" = "d8b629fb514376c675b98c1421e80b151d3817ac42d7c667717d282761418d20"
"checksum num-traits 0.1.43 (registry+https://github.com/rust-lang/crates.io-index)" = "92e5113e9fd4cc14ded8e499429f396a20f98c772a47cc8622a736e1ec843c31"
"checksum num-traits 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "0b3a5d7cc97d6d30d8b9bc8fa19bf45349ffe46241e8816f50f62f6d6aaabee1"
"checksum python27-sys 0.1.2 (git+https://github.com/indygreg/rust-cpython.git?rev=c90d65cf84abfffce7ef54476bbfed56017a2f52)" = "<none>"
"checksum regex 0.1.80 (registry+https://github.com/rust-lang/crates.io-index)" = "4fd4ace6a8cf7860714a2c2280d6c1f7e6a413486c13298bbc86fd3da019402f"
"checksum regex-syntax 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)" = "f9ec002c35e86791825ed294b50008eea9ddfc8def4420124fbc6b08db834957"
"checksum thread-id 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a9539db560102d1cef46b8b78ce737ff0bb64e7e18d35b2a5688f7d097d0ff03"
"checksum thread_local 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)" = "8576dbbfcaef9641452d5cf0df9b0e7eeab7694956dd33bb61515fb8f18cfdd5"
"checksum utf8-ranges 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "a1ca13c08c41c9c3e04224ed9ff80461d97e121589ff27c753a16cb10830ae0f"
"checksum winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "167dc9d6949a9b857f3451275e911c3f44255842c1f7a76f33c55103a909087a"
"checksum winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "2d315eee3b34aca4797b2da6b13ed88266e6d612562a0c46390af8299fc699bc"