run-command: restrict PATH search to executable files

In some situations run-command will incorrectly try (and fail) to
execute a directory instead of an executable file.  This was observed by
having a directory called "ssh" in $PATH before the real ssh and trying
to use ssh protoccol, reslting in the following:

	$ git ls-remote ssh://url
	fatal: cannot exec 'ssh': Permission denied

It ends up being worse and run-command will even try to execute a
non-executable file if it preceeds the executable version of a file on
the PATH.  For example, if PATH=~/bin1:~/bin2:~/bin3 and there exists a
directory 'git-hello' in 'bin1', a non-executable file 'git-hello' in
bin2 and an executable file 'git-hello' (which prints "Hello World!") in
bin3 the following will occur:

	$ git hello
	fatal: cannot exec 'git-hello': Permission denied

This is due to only checking 'access()' when locating an executable in
PATH, which doesn't distinguish between files and directories.  Instead
use 'is_executable()' which check that the path is to a regular,
executable file.  Now run-command won't try to execute the directory or
non-executable file 'git-hello':

	$ git hello
	Hello World!

which matches what execvp(3) would have done when asked to execute
git-hello with such a $PATH.

Reported-by: Brian Hatfield <bhatfield@google.com>
Signed-off-by: Brandon Williams <bmwill@google.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2 files changed
tree: 8959b34793de45f243d177cbec99ad2c3a4df7a4
  1. block-sha1/
  2. builtin/
  3. ci/
  4. compat/
  5. contrib/
  6. Documentation/
  7. ewah/
  8. git-gui/
  9. gitk-git/
  10. gitweb/
  11. mergetools/
  12. perl/
  13. po/
  14. ppc/
  15. refs/
  16. sha1dc/
  17. t/
  18. templates/
  19. vcs-svn/
  20. xdiff/
  21. .gitattributes
  22. .gitignore
  23. .mailmap
  24. .travis.yml
  25. abspath.c
  26. aclocal.m4
  27. advice.c
  28. advice.h
  29. alias.c
  30. alloc.c
  31. apply.c
  32. apply.h
  33. archive-tar.c
  34. archive-zip.c
  35. archive.c
  36. archive.h
  37. argv-array.c
  38. argv-array.h
  39. attr.c
  40. attr.h
  41. base85.c
  42. bisect.c
  43. bisect.h
  44. blob.c
  45. blob.h
  46. branch.c
  47. branch.h
  48. builtin.h
  49. bulk-checkin.c
  50. bulk-checkin.h
  51. bundle.c
  52. bundle.h
  53. cache-tree.c
  54. cache-tree.h
  55. cache.h
  56. check-builtins.sh
  57. check-racy.c
  58. check_bindir
  59. color.c
  60. color.h
  61. column.c
  62. column.h
  63. combine-diff.c
  64. command-list.txt
  65. commit-slab.h
  66. commit.c
  67. commit.h
  68. common-main.c
  69. config.c
  70. config.mak.in
  71. config.mak.uname
  72. configure.ac
  73. connect.c
  74. connect.h
  75. connected.c
  76. connected.h
  77. convert.c
  78. convert.h
  79. copy.c
  80. COPYING
  81. credential-cache--daemon.c
  82. credential-cache.c
  83. credential-store.c
  84. credential.c
  85. credential.h
  86. csum-file.c
  87. csum-file.h
  88. ctype.c
  89. daemon.c
  90. date.c
  91. decorate.c
  92. decorate.h
  93. delta.h
  94. diff-delta.c
  95. diff-lib.c
  96. diff-no-index.c
  97. diff.c
  98. diff.h
  99. diffcore-break.c
  100. diffcore-delta.c
  101. diffcore-order.c
  102. diffcore-pickaxe.c
  103. diffcore-rename.c
  104. diffcore.h
  105. dir-iterator.c
  106. dir-iterator.h
  107. dir.c
  108. dir.h
  109. editor.c
  110. entry.c
  111. environment.c
  112. exec_cmd.c
  113. exec_cmd.h
  114. fast-import.c
  115. fetch-pack.c
  116. fetch-pack.h
  117. fmt-merge-msg.h
  118. fsck.c
  119. fsck.h
  120. generate-cmdlist.sh
  121. gettext.c
  122. gettext.h
  123. git-add--interactive.perl
  124. git-archimport.perl
  125. git-bisect.sh
  126. git-compat-util.h
  127. git-cvsexportcommit.perl
  128. git-cvsimport.perl
  129. git-cvsserver.perl
  130. git-difftool--helper.sh
  131. git-filter-branch.sh
  132. git-instaweb.sh
  133. git-merge-octopus.sh
  134. git-merge-one-file.sh
  135. git-merge-resolve.sh
  136. git-mergetool--lib.sh
  137. git-mergetool.sh
  138. git-p4.py
  139. git-parse-remote.sh
  140. git-quiltimport.sh
  141. git-rebase--am.sh
  142. git-rebase--interactive.sh
  143. git-rebase--merge.sh
  144. git-rebase.sh
  145. git-remote-testgit.sh
  146. git-request-pull.sh
  147. git-send-email.perl
  148. git-sh-i18n.sh
  149. git-sh-setup.sh
  150. git-stash.sh
  151. git-submodule.sh
  152. git-svn.perl
  153. GIT-VERSION-GEN
  154. git-web--browse.sh
  155. git.c
  156. git.rc
  157. gpg-interface.c
  158. gpg-interface.h
  159. graph.c
  160. graph.h
  161. grep.c
  162. grep.h
  163. hash.h
  164. hashmap.c
  165. hashmap.h
  166. help.c
  167. help.h
  168. hex.c
  169. http-backend.c
  170. http-fetch.c
  171. http-push.c
  172. http-walker.c
  173. http.c
  174. http.h
  175. ident.c
  176. imap-send.c
  177. INSTALL
  178. iterator.h
  179. khash.h
  180. kwset.c
  181. kwset.h
  182. levenshtein.c
  183. levenshtein.h
  184. LGPL-2.1
  185. line-log.c
  186. line-log.h
  187. line-range.c
  188. line-range.h
  189. list-objects.c
  190. list-objects.h
  191. list.h
  192. ll-merge.c
  193. ll-merge.h
  194. lockfile.c
  195. lockfile.h
  196. log-tree.c
  197. log-tree.h
  198. mailinfo.c
  199. mailinfo.h
  200. mailmap.c
  201. mailmap.h
  202. Makefile
  203. match-trees.c
  204. merge-blobs.c
  205. merge-blobs.h
  206. merge-recursive.c
  207. merge-recursive.h
  208. merge.c
  209. mergesort.c
  210. mergesort.h
  211. mru.c
  212. mru.h
  213. name-hash.c
  214. notes-cache.c
  215. notes-cache.h
  216. notes-merge.c
  217. notes-merge.h
  218. notes-utils.c
  219. notes-utils.h
  220. notes.c
  221. notes.h
  222. object.c
  223. object.h
  224. oidset.c
  225. oidset.h
  226. pack-bitmap-write.c
  227. pack-bitmap.c
  228. pack-bitmap.h
  229. pack-check.c
  230. pack-objects.c
  231. pack-objects.h
  232. pack-revindex.c
  233. pack-revindex.h
  234. pack-write.c
  235. pack.h
  236. pager.c
  237. parse-options-cb.c
  238. parse-options.c
  239. parse-options.h
  240. patch-delta.c
  241. patch-ids.c
  242. patch-ids.h
  243. path.c
  244. pathspec.c
  245. pathspec.h
  246. pkt-line.c
  247. pkt-line.h
  248. preload-index.c
  249. pretty.c
  250. prio-queue.c
  251. prio-queue.h
  252. progress.c
  253. progress.h
  254. prompt.c
  255. prompt.h
  256. quote.c
  257. quote.h
  258. reachable.c
  259. reachable.h
  260. read-cache.c
  261. README.md
  262. ref-filter.c
  263. ref-filter.h
  264. reflog-walk.c
  265. reflog-walk.h
  266. refs.c
  267. refs.h
  268. remote-curl.c
  269. remote-testsvn.c
  270. remote.c
  271. remote.h
  272. replace_object.c
  273. rerere.c
  274. rerere.h
  275. resolve-undo.c
  276. resolve-undo.h
  277. revision.c
  278. revision.h
  279. run-command.c
  280. run-command.h
  281. send-pack.c
  282. send-pack.h
  283. sequencer.c
  284. sequencer.h
  285. server-info.c
  286. setup.c
  287. sh-i18n--envsubst.c
  288. sha1-array.c
  289. sha1-array.h
  290. sha1-lookup.c
  291. sha1-lookup.h
  292. sha1_file.c
  293. sha1_name.c
  294. shallow.c
  295. shell.c
  296. shortlog.h
  297. show-index.c
  298. sideband.c
  299. sideband.h
  300. sigchain.c
  301. sigchain.h
  302. split-index.c
  303. split-index.h
  304. strbuf.c
  305. strbuf.h
  306. streaming.c
  307. streaming.h
  308. string-list.c
  309. string-list.h
  310. submodule-config.c
  311. submodule-config.h
  312. submodule.c
  313. submodule.h
  314. symlinks.c
  315. tag.c
  316. tag.h
  317. tar.h
  318. tempfile.c
  319. tempfile.h
  320. thread-utils.c
  321. thread-utils.h
  322. tmp-objdir.c
  323. tmp-objdir.h
  324. trace.c
  325. trace.h
  326. trailer.c
  327. trailer.h
  328. transport-helper.c
  329. transport.c
  330. transport.h
  331. tree-diff.c
  332. tree-walk.c
  333. tree-walk.h
  334. tree.c
  335. tree.h
  336. unicode_width.h
  337. unimplemented.sh
  338. unix-socket.c
  339. unix-socket.h
  340. unpack-trees.c
  341. unpack-trees.h
  342. upload-pack.c
  343. url.c
  344. url.h
  345. urlmatch.c
  346. urlmatch.h
  347. usage.c
  348. userdiff.c
  349. userdiff.h
  350. utf8.c
  351. utf8.h
  352. varint.c
  353. varint.h
  354. version.c
  355. version.h
  356. versioncmp.c
  357. walker.c
  358. walker.h
  359. wildmatch.c
  360. wildmatch.h
  361. worktree.c
  362. worktree.h
  363. wrap-for-bin.sh
  364. wrapper.c
  365. write_or_die.c
  366. ws.c
  367. wt-status.c
  368. wt-status.h
  369. xdiff-interface.c
  370. xdiff-interface.h
  371. zlib.c
README.md

Git - fast, scalable, distributed revision control system

Git is a fast, scalable, distributed revision control system with an unusually rich command set that provides both high-level operations and full access to internals.

Git is an Open Source project covered by the GNU General Public License version 2 (some parts of it are under different licenses, compatible with the GPLv2). It was originally written by Linus Torvalds with help of a group of hackers around the net.

Please read the file INSTALL for installation instructions.

Many Git online resources are accessible from https://git-scm.com/ including full documentation and Git related tools.

See Documentation/gittutorial.txt to get started, then see Documentation/giteveryday.txt for a useful minimum set of commands, and Documentation/git-.txt for documentation of each command. If git has been correctly installed, then the tutorial can also be read with man gittutorial or git help tutorial, and the documentation of each command with man git-<commandname> or git help <commandname>.

CVS users may also want to read Documentation/gitcvs-migration.txt (man gitcvs-migration or git help cvs-migration if git is installed).

The user discussion and development of Git take place on the Git mailing list -- everyone is welcome to post bug reports, feature requests, comments and patches to git@vger.kernel.org (read Documentation/SubmittingPatches for instructions on patch submission). To subscribe to the list, send an email with just “subscribe git” in the body to majordomo@vger.kernel.org. The mailing list archives are available at https://public-inbox.org/git/, http://marc.info/?l=git and other archival sites.

The maintainer frequently sends the “What's cooking” reports that list the current status of various development topics to the mailing list. The discussion following them give a good reference for project status, development direction and remaining tasks.

The name “git” was given by Linus Torvalds when he wrote the very first version. He described the tool as “the stupid content tracker” and the name as (depending on your mood):

  • random three-letter combination that is pronounceable, and not actually used by any common UNIX command. The fact that it is a mispronunciation of “get” may or may not be relevant.
  • stupid. contemptible and despicable. simple. Take your pick from the dictionary of slang.
  • “global information tracker”: you're in a good mood, and it actually works for you. Angels sing, and a light suddenly fills the room.
  • “goddamn idiotic truckload of sh*t”: when it breaks