/**
* MIT/X Consortium License
*
* Copyright © 2015 Mattias Andrée <maandree@member.fsf.org>
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
#define _POSIX_C_SOURCE 200809L
#include "util.h"
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <dirent.h>
#include <unistd.h>
#include <fcntl.h>
/**
* Default value for the environment variable LIBRARIAN_PATH.
*/
#ifndef DEFAULT_PATH
# define DEFAULT_PATH "/usr/local/share/librarian:/usr/share/librarian"
#endif
/**
* A library and version range.
*/
struct library {
/**
* The name of the library.
*/
const char *name;
/**
* The lowest acceptable version.
* `NULL` if unbounded.
*/
char *lower;
/**
* The highest acceptable version.
* `NULL` if unbounded.
*/
char *upper;
/**
* Is the version stored in
* `lower` acceptable.
*/
int lower_closed;
/**
* Is the version stored in
* `ypper` acceptable.
*/
int upper_closed;
};
/**
* Structure for already located librarian files.
*/
struct found_file {
/**
* The name of the library.
*/
const char *name;
/**
* The found version of the library.
*/
char *version;
/**
* The path name of the librarian file.
*/
char *path;
};
/**
* The name of the process.
*/
static const char *argv0;
/**
* Sorted list of already located librarian files.
*/
static struct found_file *found_files = NULL;
/**
* The number of elements in `found_files`.
*/
static size_t found_files_count = 0;
/**
* Compares the name of two libraries.
*
* @param a:const struct library * One of the libraries.
* @param b:const struct library * The other library.
* @return <0: `a` < `b`.
* =0: `a` = `b`.
* >0: `a` > `b`.
*/
static int library_name_cmp(const void *a, const void *b)
{
const struct library *la = a;
const struct library *lb = b;
return strcmp(la->name, lb->name);
}
/**
* Compares the name of two `struct found_file`.
*
* @param a:const struct found_file * One of the files.
* @param b:const struct found_file * The other file.
* @return <0: `a` < `b`.
* =0: `a` = `b`.
* >0: `a` > `b`.
*/
static int found_file_name_cmp(const void *a, const void *b)
{
const struct found_file *fa = a;
const struct found_file *fb = b;
return strcmp(fa->name, fb->name);
}
/**
* Determine whether a string is the
* name of a non-reserved variable.
*
* @param s The string.
* @return 1: The string is a varible name.
* 0: The string is a library.
*/
static int is_variable(const char *s)
{
for (; *s; s++)
if (!isupper(*s) && !isdigit(*s) && !strchr("_-", *s))
return 0;
return 1;
}
/**
* Parse a library–library-version range
* argument.
*
* @param s The string.
* @param lib Output parameter for the library spec:s.
* @return 0: Successful.
* 1: Syntax error.
*/
static int parse_library(char *s, struct library *lib)
{
char *p;
char c;
memset(lib, 0, sizeof(*lib));
if (strchr(s, '/') || strchr("<>=", *s))
return 1;
lib->name = s;
p = strpbrk(s, "<>=");
if (p == NULL)
return 0;
c = *p, *p++ = '\0';
switch (c) {
case '=':
lib->lower_closed = lib->upper_closed = 1;
lib->lower = lib->upper = p;
break;
case '>':
p += lib->lower_closed = (*p == '=');
lib->lower = p;
s = strchr(p, '<');
if (s == NULL)
break;
*s++ = '\0';
if (!*(p = s))
return 0;
/* fall through */
case '<':
p += lib->upper_closed = (*p == '=');
lib->upper = p;
break;
default:
NEVER_REACHED;
break;
}
return (strpbrk(p, "<>=") || !*p);
}
/**
* Compare two version numbers that do not
* compare any does, and does not have an
* epoch.
*
* @param a One of the version numbers.
* @param b The other version number.
* @return <0: `a` < `b`.
* =0: `a` = `b`.
* >1: `a` > `b`.
*/
static int version_subcmp(char *a, char *b)
{
char *ap;
char *bp;
int r;
while (*a || *b) {
/* Compare digit part. */
/* (We must support arbitrary lenght.) */
ap = a + strspn(a, "0123456789");
bp = b + strspn(b, "0123456789");
while (*a == '0') a++;
while (*b == '0') b++;
if (ap - a < bp - b) return -1;
if (ap - a > bp - b) return +1;
TEMP_NUL(ap, TEMP_NUL(bp, r = strcmp(a, b)));
a = isdigit(*a) ? (ap + 1) : a;
b = isdigit(*b) ? (bp + 1) : b;
if (r) return r;
/* Compare letter (non-digit) part. */
ap = a + strcspn(a, "0123456789");
bp = b + strcspn(b, "0123456789");
TEMP_NUL(ap, TEMP_NUL(bp, r = strcmp(a, b)));
a = *a && !isdigit(*a) ? (ap + 1) : a;
b = *b && !isdigit(*b) ? (bp + 1) : b;
if (r) return r;
}
return 0;
}
/**
* Compare two version numbers.
*
* @param a One of the version numbers.
* @param b The other version number.
* @return <0: `a` < `b`.
* =0: `a` = `b`.
* >0: `a` > `b`.
*/
static int version_cmp(char *a, char *b)
{
#define COMPARE \
if (ap && bp) { \
TEMP_NUL(ap, TEMP_NUL(bp, r = version_subcmp(a, b))); \
} else if (ap) { \
TEMP_NUL(ap, r = version_subcmp(a, nil)); \
} else if (bp) { \
TEMP_NUL(bp, r = version_subcmp(nil, b)); \
} \
a = ap ? (ap + 1) : a; \
b = bp ? (bp + 1) : b; \
if (r) return r
#define END_AT(C) ap = strchr(a, (C)), bp = strchr(b, (C))
char *ap;
char *bp;
int r = 0;
static char nil[1] = { '\0' };
/* Compare epoch. */
END_AT(':');
COMPARE;
/* Compare non-epoch */
while (END_AT('.'), (ap || bp)) {
COMPARE;
}
END_AT('\0');
COMPARE;
return 0;
}
/**
* Test whether a version of a library is compatible.
*
* @param version The found version.
* @param required Compatible version range.
* @return 1: Version is accepted.
* 0: Version is incompatible.
*/
static int test_library_version(char *version, struct library *required)
{
int upper = required->upper ? version_cmp(version, required->upper) : -1;
int lower = required->lower ? version_cmp(version, required->lower) : +1;
upper = required->upper_closed ? (upper <= 0) : (upper < 0);
lower = required->lower_closed ? (lower >= 0) : (lower > 0);
return upper && lower;
}
/**
* Locate a librarian file in a directory.
*
* @param lib Library specification.
* @param path The pathname of the directory.
* @param oldest Are older versions prefered?
* @return The pathname of the library's librarian file.
* `NULL` on error or if not found, if not found,
* `errno` is set to 0.
*/
static char *locate_in_dir(struct library *lib, char *path, int oldest)
{
DIR *d = NULL;
struct dirent *f;
char *p;
void *new;
char *best = NULL;
char *best_ver;
int r;
d = opendir(path);
t (d == NULL);
while ((f = (errno = 0, readdir(d)))) {
p = strrchr(f->d_name, '=');
if (p == NULL)
continue;
*p = '\0';
if (strcmp(f->d_name, lib->name))
continue;
*p++ = '=';
if (!test_library_version(p, lib))
continue;
if (best != NULL) {
GET_VERSION(best_ver, best);
r = version_cmp(p, best_ver + 1);
if (!(oldest ? (r < 0) : (r > 0)))
continue;
}
new = strdup(f->d_name);
t (new == NULL);
free(best), best = new;
}
t (errno);
closedir(d), d = NULL;
if (best == NULL)
return errno = 0, NULL;
p = malloc(strlen(path) + strlen(best) + 2);
t (p == NULL);
stpcpy(stpcpy(stpcpy(p, path), "/"), best);
free(best);
return p;
fail:
RETURN (NULL) {
free(best);
if (d != NULL)
closedir(d);
}
}
/**
* Locate a librarian file on the system.
*
* @param lib Library specification.
* @param path LIBRARIAN_PATH.
* @param oldest Are older versions prefered?
* @return The pathname of the library's librarian file.
* `NULL` on error or if not found, if not found,
* `errno` is set to 0.
*/
static char *locate(struct library *lib, char *path, int oldest)
{
char *p;
char *end = path;
char *e;
char *best = NULL;
char *found;
char *old;
char *best_ver;
char *found_ver;
int r;
for (p = path; end; *e = (end ? ':' : '\0'), p = end + 1) {
end = strchr(p, ':');
e = end ? end : strchr(p, '\0');
*e = '\0';
if (!*p)
continue;
found = locate_in_dir(lib, p, oldest);
if (found == NULL) {
t (errno);
continue;
}
old = found;
if (best == NULL) {
old = best, best = found;
} else {
GET_VERSION(best_ver, best);
GET_VERSION(found_ver, found);
r = version_cmp(found_ver + 1, best_ver + 1);
if (oldest ? (r < 0) : (r > 0))
old = best, best = found;
}
free(old);
}
return errno = 0, best;
fail:
RETURN (NULL)
free(best);
}
/**
* Find librarian files for all libraries.
*
* Found files are appended to `found_files`.
*
* @param libraries The sought libraries.
* @param n The number of elements in `libraries`.
* @param path LIBRARIAN_PATH.
* @param oldest Are older versions prefered?
* @return 0: Successful and found all files.
* -1 and !errno: Did not find all files, but otherwise successful.
* -1 and errno: An error occurred
*/
static int find_librarian_files(struct library *libraries, size_t n, char *path, int oldest)
{
size_t i;
char *best = NULL;
char *found;
char *best_ver;
char *found_ver;
const char *last = NULL;
size_t ffc = found_files_count;
int r;
struct found_file f;
struct found_file *have;
qsort(libraries, n, sizeof(*libraries), library_name_cmp);
qsort(found_files, ffc, sizeof(*found_files), found_file_name_cmp);
REALLOC(found_files, ffc + n);
for (i = 0; i < n; i++) {
f.name = libraries[i].name;
have = bsearch(&f, found_files, ffc, sizeof(*found_files), found_file_name_cmp);
if (have) {
if (test_library_version(have->version, libraries + i))
continue;
goto not_this_range;
}
found = locate(libraries + i, path, oldest);
t (!found && errno);
if (found == NULL)
goto not_this_range;
if (last && !strcmp(f.name, last)) {
GET_VERSION(best_ver, best);
GET_VERSION(found_ver, found);
r = version_cmp(found + 1, best_ver + 1);
if (!(oldest ? (r < 0) : (r > 0)))
continue;
free(best);
} else {
last = f.name, found_files_count++;
}
GET_VERSION(found_ver, found);
found_files[found_files_count - 1].name = f.name;
found_files[found_files_count - 1].version = found_ver + 1;
found_files[found_files_count - 1].path = best = found;
continue;
not_this_range:
if ((i + 1 == n) || strcmp(f.name, libraries[i + 1].name))
goto not_found;
continue;
}
return 0;
not_found:
if (libraries[i].upper == libraries[i].lower) {
fprintf(stderr, "%s: cannot find library: %s%s%s", argv0,
libraries[i].name, libraries[i].upper ? "=" : "",
libraries[i].upper ? libraries[i].upper : "");
} else {
fprintf(stderr, "%s: cannot find library: %s%s%s%s%s%s%s", argv0,
libraries[i].name,
libraries[i].lower ? ">" : "", libraries[i].lower_closed ? "=" : "",
libraries[i].lower ? libraries[i].lower : "",
libraries[i].upper ? "<" : "", libraries[i].upper_closed ? "=" : "",
libraries[i].upper ? libraries[i].upper : "");
}
errno = 0;
fail:
return -1;
}
/**
* Read the value of a variable in a file.
*
* @param path The pathname of the file to read.
* @param var The variable to retrieve
* @return The value of variable. `NULL` on error or if
* not found, `errno` is set to 0 if not found.
*/
static char *find_variable(const char *path, const char *var)
{
int fd = -1;
size_t ptr = 0, size = 0, len;
char *buffer = NULL;
char *p;
char *q;
char *sought = NULL;
ssize_t n;
fd = open(path, O_RDONLY);
t (fd == -1);
for (;;) {
MAYBE_GROW(buffer, ptr, size, 512);
n = read(fd, buffer + ptr, size - ptr);
t (n < 0);
if (n == 0)
break;
ptr += (size_t)n;
}
close(fd), fd = -1;
REALLOC(buffer, ptr + 3);
buffer[ptr++] = '\n';
buffer[ptr++] = '\0';
memmove(buffer + 1, buffer, ptr);
*buffer = '\n';
sought = malloc(strlen(var) + 2);
t (sought == NULL);
sought[0] = '\n';
strcpy(sought + 1, var);
len = strlen(sought);
for (p = buffer; p;) {
p = strstr(p, sought);
if (p == NULL)
break;
if (!isspace(p[len])) {
p = strchr(p + 1, '\n');
continue;
}
p += len + 1;
q = strchr(p, '\n');
*q = '\0';
break;
}
if (p != NULL) {
p = strdup(p);
t (p == NULL);
}
free(sought);
free(buffer);
return p;
fail:
RETURN (NULL) {
if (fd >= 0)
close(fd);
free(buffer);
free(sought);
}
}
/**
* Get variables values stored in librarian files.
*
* @param vars Pointer to the first variable.
* @param vars_end Pointer to just after the last variable.
* @param files_start The index of the first file in `found_files`
* for which variables should be retrieved.
* @return String with all variables, `NULL` on error.
*/
static char *get_variables(const char **vars, const char **vars_end, size_t files_start)
{
char *path;
const char **var;
char **parts = NULL;
char *part;
size_t ptr = 0;
size_t size = 0;
size_t len = 0;
char *rc;
char *p;
while (files_start < found_files_count) {
path = found_files[files_start++].path;
for (var = vars; var != vars_end; var++) {
part = find_variable(path, *var);
t (!part && errno);
if (!part || !*part)
continue;
MAYBE_GROW(parts, ptr, size, 8);
len += strlen(part) + 1;
parts[ptr++] = part;
}
}
if (len == 0)
return strdup("");
p = rc = malloc(len);
t (rc == NULL);
for (size = ptr, ptr = 0; ptr < size; ptr++) {
p = stpcpy(p, parts[ptr]);
*p++ = ' ';
free(parts[ptr]);
}
free(parts);
p[-1] = 0;
return rc;
fail:
RETURN (NULL) {
while (ptr--)
free(parts[ptr]);
free(parts);
}
}
/**
* @return 0: Program was successful.
* 1: An error occurred.
* 2: A library was not found.
* 3: Usage error.
*/
int main(int argc, char *argv[])
{
int dashed = 0, f_deps = 0, f_locate = 0, f_oldest = 0;
char *arg;
char **args = argv;
char **args_last = args;
const char **variables = (const char **)argv;
const char **variables_last = variables;
struct library *libraries = NULL;
size_t libraries_ptr = 0;
size_t libraries_size = 0;
const char *path_;
char *path = NULL;
int rc;
size_t start_files;
size_t start_libs, n;
char *data = NULL;
char *s;
char *end;
void** free_this = NULL;
size_t free_this_ptr = 0;
size_t free_this_size = 0;
const char *deps_string = "deps";
/* Parse arguments. */
argv0 = argv ? (argc--, *argv++) : "pp";
while (argc--) {
if (!dashed && !strcmp(*argv, "--")) {
dashed = 1;
argv++;
} else if (!dashed && (**argv == '-')) {
arg = *argv++;
if (!*arg)
goto usage;
for (arg++; *arg; arg++) {
if (*arg == 'd') f_deps = 1;
else if (*arg == 'l') f_locate = 1;
else if (*arg == 'o') f_oldest = 1;
else goto usage;
}
} else {
*args_last++ = *argv++;
}
}
if (f_deps && f_locate)
goto usage;
/* Parse VARIABLE and LIBRARY arguments. */
libraries_size = (size_t)(args_last - args);
libraries = malloc(libraries_size * sizeof(*libraries));
t (libraries == NULL);
for (; args != args_last; args++) {
if (is_variable(*args))
*variables_last++ = *args;
else if (parse_library(*args, libraries + libraries_ptr++))
goto usage;
}
/* Get LIBRARIAN_PATH. */
path_ = getenv("LIBRARIAN_PATH");
if (!path_ || !*path_)
path_ = DEFAULT_PATH;
path = strdup(path_);
t (path == NULL);
/* Find librarian files. */
for (start_libs = 0; (n = libraries_ptr - start_libs);) {
start_files = found_files_count;
if (find_librarian_files(libraries + start_libs, n, path, f_oldest)) {
t (errno);
goto not_found;
}
start_libs += n;
if (f_locate || !f_deps)
break;
data = get_variables(&deps_string, 1 + &deps_string, start_files);
t (data == NULL);
for (end = s = data; end; s = end + 1) {
while (isspace(*s))
s++;
if ((end = strpbrk(s, " \t\r\n\f\v")))
*end = '\0';
MAYBE_GROW(libraries, libraries_ptr, libraries_size, 1);
if (*s && parse_library(s, libraries + libraries_ptr++))
goto not_found;
}
MAYBE_GROW(free_this, free_this_ptr, free_this_size, 4);
free_this[free_this_ptr++] = data, data = NULL;
}
if (f_locate) {
for (n = 0; n < found_files_count; n++)
t (printf("%s\n", found_files[n].path) < 0);
goto done;
}
/* Print requested data. */
data = get_variables(variables, variables_last, 0);
t (data == NULL);
t (printf("%s\n", data) < 0);
done:
rc = 0;
goto cleanup;
fail:
perror(argv0);
rc = 1;
goto cleanup;
not_found:
rc = 2;
goto cleanup;
usage:
fprintf(stderr, "%s: Invalid arguments, see `man 1 librarian'.\n", argv0);
rc = 3;
goto cleanup;
cleanup:
while (found_files_count--)
free(found_files[found_files_count].path);
free(found_files);
while (free_this_ptr--)
free(free_this[free_this_ptr]);
free(free_this);
free(libraries);
free(path);
free(data);
return rc;
}
