Implement normalize_absolute_path

normalize_absolute_path removes several oddities form absolute paths,
giving nice clean paths like "/dir/sub1/sub2".  Also add a test case
for this utility, based on a new test program (in the style of test-sha1).

Signed-off-by: David Reiss <dreiss@facebook.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
David Reiss 2008-05-19 23:48:54 -07:00 committed by Junio C Hamano
parent 377d9c409f
commit ae299be0e5
6 changed files with 109 additions and 1 deletions

1
.gitignore vendored
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@ -150,6 +150,7 @@ test-dump-cache-tree
test-genrandom test-genrandom
test-match-trees test-match-trees
test-parse-options test-parse-options
test-path-utils
test-sha1 test-sha1
common-cmds.h common-cmds.h
*.tar.gz *.tar.gz

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@ -1186,7 +1186,7 @@ endif
### Testing rules ### Testing rules
TEST_PROGRAMS = test-chmtime$X test-genrandom$X test-date$X test-delta$X test-sha1$X test-match-trees$X test-absolute-path$X test-parse-options$X TEST_PROGRAMS = test-chmtime$X test-genrandom$X test-date$X test-delta$X test-sha1$X test-match-trees$X test-absolute-path$X test-parse-options$X test-path-utils$X
all:: $(TEST_PROGRAMS) all:: $(TEST_PROGRAMS)

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@ -514,6 +514,7 @@ static inline int is_absolute_path(const char *path)
return path[0] == '/'; return path[0] == '/';
} }
const char *make_absolute_path(const char *path); const char *make_absolute_path(const char *path);
int normalize_absolute_path(char *buf, const char *path);
/* Read and unpack a sha1 file into memory, write memory to a sha1 file */ /* Read and unpack a sha1 file into memory, write memory to a sha1 file */
extern int sha1_object_info(const unsigned char *, unsigned long *); extern int sha1_object_info(const unsigned char *, unsigned long *);

53
path.c
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@ -357,3 +357,56 @@ const char *make_absolute_path(const char *path)
return buf; return buf;
} }
/*
* path = absolute path
* buf = buffer of at least max(2, strlen(path)+1) bytes
* It is okay if buf == path, but they should not overlap otherwise.
*
* Performs the following normalizations on path, storing the result in buf:
* - Removes trailing slashes.
* - Removes empty components.
* - Removes "." components.
* - Removes ".." components, and the components the precede them.
* "" and paths that contain only slashes are normalized to "/".
* Returns the length of the output.
*
* Note that this function is purely textual. It does not follow symlinks,
* verify the existence of the path, or make any system calls.
*/
int normalize_absolute_path(char *buf, const char *path)
{
const char *comp_start = path, *comp_end = path;
char *dst = buf;
int comp_len;
assert(buf);
assert(path);
while (*comp_start) {
assert(*comp_start == '/');
while (*++comp_end && *comp_end != '/')
; /* nothing */
comp_len = comp_end - comp_start;
if (!strncmp("/", comp_start, comp_len) ||
!strncmp("/.", comp_start, comp_len))
goto next;
if (!strncmp("/..", comp_start, comp_len)) {
while (dst > buf && *--dst != '/')
; /* nothing */
goto next;
}
memcpy(dst, comp_start, comp_len);
dst += comp_len;
next:
comp_start = comp_end;
}
if (dst == buf)
*dst++ = '/';
*dst = '\0';
return dst - buf;
}

40
t/t0060-path-utils.sh Executable file
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@ -0,0 +1,40 @@
#!/bin/sh
#
# Copyright (c) 2008 David Reiss
#
test_description='Test various path utilities'
. ./test-lib.sh
norm_abs() {
test_expect_success "normalize absolute" \
"test \$(test-path-utils normalize_absolute_path '$1') = '$2'"
}
norm_abs "" /
norm_abs / /
norm_abs // /
norm_abs /// /
norm_abs /. /
norm_abs /./ /
norm_abs /./.. /
norm_abs /../. /
norm_abs /./../.// /
norm_abs /dir/.. /
norm_abs /dir/sub/../.. /
norm_abs /dir /dir
norm_abs /dir// /dir
norm_abs /./dir /dir
norm_abs /dir/. /dir
norm_abs /dir///./ /dir
norm_abs /dir//sub/.. /dir
norm_abs /dir/sub/../ /dir
norm_abs //dir/sub/../. /dir
norm_abs /dir/s1/../s2/ /dir/s2
norm_abs /d1/s1///s2/..//../s3/ /d1/s3
norm_abs /d1/s1//../s2/../../d2 /d2
norm_abs /d1/.../d2 /d1/.../d2
norm_abs /d1/..././../d2 /d1/d2
test_done

13
test-path-utils.c Normal file
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@ -0,0 +1,13 @@
#include "cache.h"
int main(int argc, char **argv)
{
if (argc == 3 && !strcmp(argv[1], "normalize_absolute_path")) {
char *buf = xmalloc(strlen(argv[2])+1);
int rv = normalize_absolute_path(buf, argv[2]);
assert(strlen(buf) == rv);
puts(buf);
}
return 0;
}