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/*
* Copyright (c) 2008 Apple Inc. All rights reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this
* file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_LICENSE_HEADER_END@
*/
#include <fts.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>
static void usage() {
fprintf(stderr, "usage: path_helper [-c | -s]");
exit(1);
}
// Append path segment if it does not exist. Reallocate
// the path buffer as necessary.
int append_path_segment(char** path, const char* segment) {
if (*path == NULL || segment == NULL) return -1;
size_t pathlen = strlen(*path);
size_t seglen = strlen(segment);
if (seglen == 0) return 0;
// Does the segment already exist in the path?
// (^|:)segment(:|$)
char* match = strstr(*path, segment);
while (match) {
if ((match == *path || match[-1] == ':') &&
(match[seglen] == ':' || match[seglen] == 0)) {
return 0;
}
match = strstr(match+1, segment);
}
// size = pathlen + ':' + segment + '\0'
size_t size = pathlen + seglen + 2;
*path = reallocf(*path, size);
if (*path == NULL) return -1;
if (pathlen > 0) strlcat(*path, ":", size);
strlcat(*path, segment, size);
return 0;
}
// Convert fgetln output into a sanitized segment
// escape quotes, dollars, etc.
char* read_segment(const char* line, size_t len) {
int escapes = 0;
size_t i, j;
for (i = 0; i < len; ++i) {
char c = line[i];
if (c == '\"' || c == '\'' || c == '$') {
++escapes;
}
}
size_t size = len + escapes + 1;
char* segment = calloc(1, size);
if (segment == NULL) return NULL;
for (i = 0, j = 0; i < len; ++i, ++j) {
char c = line[i];
if (c == '\"' || c == '\'' || c == '$') {
segment[j++] = '\\';
segment[j] = c;
} else if (c == '\n') {
segment[j] = 0;
break;
} else {
segment[j] = line[i];
}
}
return segment;
}
// Construct a path variable, starting with the contents
// of the given environment variable, adding the contents
// of the default file and files in the path directory.
char* construct_path(char* env_var, char* defaults_path, char* dir_path) {
FTS* fts;
FTSENT* ent;
char* result = calloc(sizeof(char), 1);
char* dirpathv[] = { defaults_path, dir_path, NULL };
fts = fts_open(dirpathv, FTS_PHYSICAL | FTS_XDEV, NULL);
if (!fts) {
perror(dir_path);
return NULL;
}
while ((ent = fts_read(fts)) != NULL) {
// only interested in regular files, one level deep
if (ent->fts_info != FTS_F) {
if (ent->fts_level >= 1) fts_set(fts, ent, FTS_SKIP);
continue;
}
FILE* f = fopen(ent->fts_accpath, "r");
if (f == NULL) {
perror(ent->fts_accpath);
continue;
}
for (;;) {
size_t len;
char* line = fgetln(f, &len);
if (line == NULL) break;
char* segment = read_segment(line, len);
append_path_segment(&result, segment);
}
fclose(f);
}
fts_close(fts);
// merge in any existing custom PATH elemenets
char* str = getenv(env_var);
if (str) str = strdup(str);
while (str) {
char* sep = strchr(str, ':');
if (sep) *sep = 0;
append_path_segment(&result, str);
if (sep) {
str = sep + 1;
} else {
str = NULL;
}
}
return result;
}
enum {
STYLE_CSH,
STYLE_SH
};
int main(int argc, char* argv[]) {
int style = STYLE_SH;
if (argc > 2) usage();
// default to csh style, if $SHELL ends with "csh".
char* shell = getenv("SHELL");
if (shell) {
char* str = strstr(shell, "csh");
if (str) style = STYLE_CSH;
}
if (argc == 2 && strcmp(argv[1], "-c") == 0) style = STYLE_CSH;
if (argc == 2 && strcmp(argv[1], "-s") == 0) style = STYLE_SH;
char* path = construct_path("PATH", "/etc/paths", "/etc/paths.d");
char* manpath = NULL;
// only adjust manpath if already set
int do_manpath = (getenv("MANPATH") != NULL);
if (do_manpath) {
manpath = construct_path("MANPATH", "/etc/manpaths", "/etc/manpaths.d");
}
if (style == STYLE_CSH) {
printf("setenv PATH \"%s\";\n", path);
if (do_manpath) printf("setenv MANPATH \"%s\";\n", manpath);
} else {
printf("PATH=\"%s\"; export PATH;\n", path);
if (do_manpath) printf("MANPATH=\"%s\"; export MANPATH;\n", manpath);
}
return 0;
}
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