From: Alan Donovan Date: Wed, 28 Aug 2024 22:13:05 +0000 (-0400) Subject: os/exec: document interaction of Dir, PWD, os.Getwd and C X-Git-Tag: go1.24rc1~1087 X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=00c48ad6155a209841dbfb6154f650c622aaa10b;p=gostls13.git os/exec: document interaction of Dir, PWD, os.Getwd and C Fixes #68000 Change-Id: Ie70a8ecc9573b2a4cf57119bda57e0af5e16c42f Reviewed-on: https://go-review.googlesource.com/c/go/+/609395 LUCI-TryBot-Result: Go LUCI Reviewed-by: Ian Lance Taylor --- diff --git a/src/os/exec/exec.go b/src/os/exec/exec.go index da9f68fe28..363759546f 100644 --- a/src/os/exec/exec.go +++ b/src/os/exec/exec.go @@ -166,11 +166,27 @@ type Cmd struct { // value in the slice for each duplicate key is used. // As a special case on Windows, SYSTEMROOT is always added if // missing and not explicitly set to the empty string. + // + // See also the Dir field, which may set PWD in the environment. Env []string // Dir specifies the working directory of the command. // If Dir is the empty string, Run runs the command in the // calling process's current directory. + // + // On Unix systems, the value of Dir also determines the + // child process's PWD environment variable if not otherwise + // specified. A Unix process represents its working directory + // not by name but as an implicit reference to a node in the + // file tree. So, if the child process obtains its working + // directory by calling a function such as C's getcwd, which + // computes the canonical name by walking up the file tree, it + // will not recover the original value of Dir if that value + // was an alias involving symbolic links. However, if the + // child process calls Go's [os.Getwd] or GNU C's + // get_current_dir_name, and the value of PWD is an alias for + // the current directory, those functions will return the + // value of PWD, which matches the value of Dir. Dir string // Stdin specifies the process's standard input.