Description
Summary
findExe works well, but it would be nice to also have an equivalent of which -a - ie like findExe but returning all executables (as a seq or iterator).
Description
I propose a simple extension of the findExe, named eg findExeAll, which either yields all found executables, or returns a seq. To do this we only need a simple modification to the findExe code, to either assemble a seq or yield all found items instead of exiting once the first one is found.
This could be implemented as a flag to findExe, such as returnFirst or similar, though then the return type becomes ambiguous, so two functions would seem to make more sense... perhaps one that yields all results, and a second that simply takes the next value of the yielding function.
Here's a possible implementation:
const ExeExtsSeq: seq[string] = toSeq(ExeExts)
proc iterExes(exe: string, followSymlinks: bool = true;
extensions: seq[string]=ExeExtsSeq): iterator () : string {.
tags: [ReadDirEffect, ReadEnvEffect, ReadIOEffect], noNimJs.} =
## Searches for `exe` in the current working directory and then
## in directories listed in the ``PATH`` environment variable.
##
## `exe` is added the `ExeExts <#ExeExts>`_ file extensions if it has none.
##
## If the system supports symlinks it also resolves them until it
## meets the actual file. This behavior can be disabled if desired
## by setting `followSymlinks = false`.
if exe.len == 0: return
result = iterator() : string =
template checkCurrentDir() =
for ext in extensions:
let exe_with_ext = addFileExt(exe, ext)
if fileExists(exe_with_ext):
yield exe_with_ext
when defined(posix):
if '/' in exe: checkCurrentDir()
else:
checkCurrentDir()
let path = getEnv("PATH")
for candidate in split(path, PathSep):
if candidate.len == 0: continue
when defined(windows):
var x = (if candidate[0] == '"' and candidate[^1] == '"':
substr(candidate, 1, candidate.len-2) else: candidate) /
exe
else:
var x = expandTilde(candidate) / exe
for ext in extensions:
var x = addFileExt(x, ext)
if not fileExists(x):
continue
when not defined(windows):
while followSymlinks: # doubles as if here
if x.symlinkExists:
var r = newString(maxSymlinkLen)
var len = readlink(x, r, maxSymlinkLen)
if len < 0:
raiseOSError(osLastError(), exe)
if len > maxSymlinkLen:
r = newString(len+1)
len = readlink(x, r, len)
setLen(r, len)
if isAbsolute(r):
x = r
else:
x = parentDir(x) / r
else:
break
yield x
proc findExe*(exe: string, followSymlinks: bool = true;
extensions: seq[string]=ExeExtsSeq): string {.
tags: [ReadDirEffect, ReadEnvEffect, ReadIOEffect], noNimJs.} =
## Searches for `exe` in the current working directory and then
## in directories listed in the ``PATH`` environment variable.
##
## Returns `""` if the `exe` cannot be found. `exe`
## is added the `ExeExts <#ExeExts>`_ file extensions if it has none.
##
## If the system supports symlinks it also resolves them until it
## meets the actual file. This behavior can be disabled if desired
## by setting `followSymlinks = false`.
return iterExes(exe, followSymlinks, extensions)()
proc findExeAll*(exe: string, followSymlinks: bool = true;
extensions: seq[string]=ExeExtsSeq): seq[string] {.
tags: [ReadDirEffect, ReadEnvEffect, ReadIOEffect], noNimJs.} =
## Searches for `exe` in the current working directory and then
## in directories listed in the ``PATH`` environment variable.
##
## Returns `""` if the `exe` cannot be found. `exe`
## is added the `ExeExts <#ExeExts>`_ file extensions if it has none.
##
## If the system supports symlinks it also resolves them until it
## meets the actual file. This behavior can be disabled if desired
## by setting `followSymlinks = false`.
var results : seq[string]
let exes = iterExes(exe, followSymlinks, extensions)
for exe in exes():
results.add(exe)
return results
Alternatives
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Standard Output Examples
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Backwards Compatibility
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Links
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