diff options
Diffstat (limited to 'abspath.c')
-rw-r--r-- | abspath.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/abspath.c b/abspath.c new file mode 100644 index 0000000000..2825de8591 --- /dev/null +++ b/abspath.c @@ -0,0 +1,180 @@ +#include "cache.h" + +/* + * Do not use this for inspecting *tracked* content. When path is a + * symlink to a directory, we do not want to say it is a directory when + * dealing with tracked content in the working tree. + */ +int is_directory(const char *path) +{ + struct stat st; + return (!stat(path, &st) && S_ISDIR(st.st_mode)); +} + +/* We allow "recursive" symbolic links. Only within reason, though. */ +#define MAXDEPTH 5 + +/* + * Return the real path (i.e., absolute path, with symlinks resolved + * and extra slashes removed) equivalent to the specified path. (If + * you want an absolute path but don't mind links, use + * absolute_path().) The return value is a pointer to a static + * buffer. + * + * The input and all intermediate paths must be shorter than MAX_PATH. + * The directory part of path (i.e., everything up to the last + * dir_sep) must denote a valid, existing directory, but the last + * component need not exist. If die_on_error is set, then die with an + * informative error message if there is a problem. Otherwise, return + * NULL on errors (without generating any output). + * + * If path is our buffer, then return path, as it's already what the + * user wants. + */ +static const char *real_path_internal(const char *path, int die_on_error) +{ + static struct strbuf sb = STRBUF_INIT; + char *retval = NULL; + + /* + * If we have to temporarily chdir(), store the original CWD + * here so that we can chdir() back to it at the end of the + * function: + */ + struct strbuf cwd = STRBUF_INIT; + + int depth = MAXDEPTH; + char *last_elem = NULL; + struct stat st; + + /* We've already done it */ + if (path == sb.buf) + return path; + + if (!*path) { + if (die_on_error) + die("The empty string is not a valid path"); + else + goto error_out; + } + + strbuf_reset(&sb); + strbuf_addstr(&sb, path); + + while (depth--) { + if (!is_directory(sb.buf)) { + char *last_slash = find_last_dir_sep(sb.buf); + if (last_slash) { + last_elem = xstrdup(last_slash + 1); + strbuf_setlen(&sb, last_slash - sb.buf + 1); + } else { + last_elem = xmemdupz(sb.buf, sb.len); + strbuf_reset(&sb); + } + } + + if (sb.len) { + if (!cwd.len && strbuf_getcwd(&cwd)) { + if (die_on_error) + die_errno("Could not get current working directory"); + else + goto error_out; + } + + if (chdir(sb.buf)) { + if (die_on_error) + die_errno("Could not switch to '%s'", + sb.buf); + else + goto error_out; + } + } + if (strbuf_getcwd(&sb)) { + if (die_on_error) + die_errno("Could not get current working directory"); + else + goto error_out; + } + + if (last_elem) { + if (sb.len && !is_dir_sep(sb.buf[sb.len - 1])) + strbuf_addch(&sb, '/'); + strbuf_addstr(&sb, last_elem); + free(last_elem); + last_elem = NULL; + } + + if (!lstat(sb.buf, &st) && S_ISLNK(st.st_mode)) { + struct strbuf next_sb = STRBUF_INIT; + ssize_t len = strbuf_readlink(&next_sb, sb.buf, 0); + if (len < 0) { + if (die_on_error) + die_errno("Invalid symlink '%s'", + sb.buf); + else + goto error_out; + } + strbuf_swap(&sb, &next_sb); + strbuf_release(&next_sb); + } else + break; + } + + retval = sb.buf; +error_out: + free(last_elem); + if (cwd.len && chdir(cwd.buf)) + die_errno("Could not change back to '%s'", cwd.buf); + strbuf_release(&cwd); + + return retval; +} + +const char *real_path(const char *path) +{ + return real_path_internal(path, 1); +} + +const char *real_path_if_valid(const char *path) +{ + return real_path_internal(path, 0); +} + +/* + * Use this to get an absolute path from a relative one. If you want + * to resolve links, you should use real_path. + */ +const char *absolute_path(const char *path) +{ + static struct strbuf sb = STRBUF_INIT; + strbuf_reset(&sb); + strbuf_add_absolute_path(&sb, path); + return sb.buf; +} + +/* + * Unlike prefix_path, this should be used if the named file does + * not have to interact with index entry; i.e. name of a random file + * on the filesystem. + */ +const char *prefix_filename(const char *pfx, int pfx_len, const char *arg) +{ + static struct strbuf path = STRBUF_INIT; +#ifndef GIT_WINDOWS_NATIVE + if (!pfx_len || is_absolute_path(arg)) + return arg; + strbuf_reset(&path); + strbuf_add(&path, pfx, pfx_len); + strbuf_addstr(&path, arg); +#else + /* don't add prefix to absolute paths, but still replace '\' by '/' */ + strbuf_reset(&path); + if (is_absolute_path(arg)) + pfx_len = 0; + else if (pfx_len) + strbuf_add(&path, pfx, pfx_len); + strbuf_addstr(&path, arg); + convert_slashes(path.buf + pfx_len); +#endif + return path.buf; +} |