使用Git Grep进行搜索

用git grep 命令查找Git库里面的某段文字是很方便的. 当然, 你也可以用unix下的'grep'命令进行搜索, 但是'git grep'命令能让你不用签出(checkout)历史文件, 就能查找它们.

例如, 你要看 git.git　这个仓库里每个使用'xmmap'函数的地方, 你可以运行下面的命令:

$ git grep xmmap
config.c:               contents = xmmap(NULL, contents_sz, PROT_READ,
diff.c:         s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
git-compat-util.h:extern void *xmmap(void *start, size_t length, int prot, int fla
read-cache.c:   mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE,
refs.c: log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
sha1_file.c:    map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
sha1_file.c:    idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
sha1_file.c:                    win->base = xmmap(NULL, win->len,
sha1_file.c:                    map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, f
sha1_file.c:            buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
wrapper.c:void *xmmap(void *start, size_t length,

如果你要显示行号, 你可以添加'-n'选项:

$>git grep -n xmmap
config.c:1016:          contents = xmmap(NULL, contents_sz, PROT_READ,
diff.c:1833:            s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd,
git-compat-util.h:291:extern void *xmmap(void *start, size_t length, int prot, int
read-cache.c:1178:      mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_
refs.c:1345:    log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
sha1_file.c:377:        map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
sha1_file.c:479:        idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd
sha1_file.c:780:                        win->base = xmmap(NULL, win->len,
sha1_file.c:1076:                       map = xmmap(NULL, *size, PROT_READ, MAP_PR
sha1_file.c:2393:               buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd
wrapper.c:89:void *xmmap(void *start, size_t length,

如果我们想只显示文件名, 我们可以使用'--name-only'选项:

$>git grep --name-only xmmap
config.c
diff.c
git-compat-util.h
read-cache.c
refs.c
sha1_file.c
wrapper.c

我们可以用'-c'选项,可以查看每个文件里有多少行匹配内容(line matches):

$>git grep -c xmmap
config.c:1
diff.c:1
git-compat-util.h:1
read-cache.c:1
refs.c:1
sha1_file.c:5
wrapper.c:1

现在, 如果我们要查找git仓库里某个特定版本里的内容, 我们可以像下面一样在命令行末尾加上标签名(tag reference):

$ git grep xmmap v1.5.0
v1.5.0:config.c:                contents = xmmap(NULL, st.st_size, PROT_READ,
v1.5.0:diff.c:          s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd,
v1.5.0:git-compat-util.h:static inline void *xmmap(void *start, size_t length,
v1.5.0:read-cache.c:                    cache_mmap = xmmap(NULL, cache_mmap_size, 
v1.5.0:refs.c:  log_mapped = xmmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, logfd
v1.5.0:sha1_file.c:     map = xmmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 
v1.5.0:sha1_file.c:     idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd
v1.5.0:sha1_file.c:                     win->base = xmmap(NULL, win->len,
v1.5.0:sha1_file.c:     map = xmmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 
v1.5.0:sha1_file.c:             buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd

我可以看到"1.5.0版"和当前版本间一些区别: 在“1.5.0版"中, xmmap没有在wrapper.c中出现.

我们也可以组合一些搜索条件, 下面的命令就是查找我们在仓库的哪个地方定义了'SORT_DIRENT'.

$ git grep -e '#define' --and -e SORT_DIRENT
builtin-fsck.c:#define SORT_DIRENT 0
builtin-fsck.c:#define SORT_DIRENT 1

我不但可以进行“与"(both)条件搜索操作，也可以进行"或"(either)条件搜索操作.

$ git grep --all-match -e '#define' -e SORT_DIRENT
builtin-fsck.c:#define REACHABLE 0x0001
builtin-fsck.c:#define SEEN      0x0002
builtin-fsck.c:#define ERROR_OBJECT 01
builtin-fsck.c:#define ERROR_REACHABLE 02
builtin-fsck.c:#define SORT_DIRENT 0
builtin-fsck.c:#define DIRENT_SORT_HINT(de) 0
builtin-fsck.c:#define SORT_DIRENT 1
builtin-fsck.c:#define DIRENT_SORT_HINT(de) ((de)->d_ino)
builtin-fsck.c:#define MAX_SHA1_ENTRIES (1024)
builtin-fsck.c: if (SORT_DIRENT)

我们也可以查找出符合一个条件(term)且符合两个条件(terms)之一的文件行.　例如我们要找出名字中含有‘PATH'或是'MAX'的常量定义:

$ git grep -e '#define' --and \( -e PATH -e MAX \) 
abspath.c:#define MAXDEPTH 5
builtin-blame.c:#define MORE_THAN_ONE_PATH      (1u<<13)
builtin-blame.c:#define MAXSG 16
builtin-describe.c:#define MAX_TAGS     (FLAG_BITS - 1)
builtin-fetch-pack.c:#define MAX_IN_VAIN 256
builtin-fsck.c:#define MAX_SHA1_ENTRIES (1024)
...

译者注:　就是"与"条件搜索和"或"条件搜索可以组合使用.