From 8b930a0c94ba9013d015c735cfc38c40b151f491 Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Mon, 26 May 2003 13:45:00 +0000 Subject: * Some refactoring. --- src/util.cc | 94 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 94 insertions(+) create mode 100644 src/util.cc (limited to 'src/util.cc') diff --git a/src/util.cc b/src/util.cc new file mode 100644 index 0000000000..4b7bbac3dd --- /dev/null +++ b/src/util.cc @@ -0,0 +1,94 @@ +#include "util.hh" + + +string thisSystem = SYSTEM; +string nixHomeDir = "/nix"; +string nixHomeDirEnvVar = "NIX"; + + + +string absPath(string filename, string dir) +{ + if (filename[0] != '/') { + if (dir == "") { + char buf[PATH_MAX]; + if (!getcwd(buf, sizeof(buf))) + throw Error("cannot get cwd"); + dir = buf; + } + filename = dir + "/" + filename; + /* !!! canonicalise */ + char resolved[PATH_MAX]; + if (!realpath(filename.c_str(), resolved)) + throw Error("cannot canonicalise path " + filename); + filename = resolved; + } + return filename; +} + + +static string printHash(unsigned char * buf) +{ + ostringstream str; + for (int i = 0; i < 16; i++) { + str.fill('0'); + str.width(2); + str << hex << (int) buf[i]; + } + return str.str(); +} + + +/* Verify that a reference is valid (that is, is a MD5 hash code). */ +bool isHash(const string & s) +{ + if (s.length() != 32) return false; + for (int i = 0; i < 32; i++) { + char c = s[i]; + if (!((c >= '0' && c <= '9') || + (c >= 'a' && c <= 'f'))) + return false; + } + return true; +} + + +void checkHash(const string & s) +{ + if (!isHash(s)) throw BadRefError("invalid reference: " + s); +} + + +/* Compute the MD5 hash of a file. */ +string hashFile(string filename) +{ + unsigned char hash[16]; + FILE * file = fopen(filename.c_str(), "rb"); + if (!file) + throw BadRefError("file `" + filename + "' does not exist"); + int err = md5_stream(file, hash); + fclose(file); + if (err) throw BadRefError("cannot hash file"); + return printHash(hash); +} + + + +/* Return the directory part of the given path, i.e., everything + before the final `/'. */ +string dirOf(string s) +{ + unsigned int pos = s.rfind('/'); + if (pos == string::npos) throw Error("invalid file name"); + return string(s, 0, pos); +} + + +/* Return the base name of the given path, i.e., everything following + the final `/'. */ +string baseNameOf(string s) +{ + unsigned int pos = s.rfind('/'); + if (pos == string::npos) throw Error("invalid file name"); + return string(s, pos + 1); +} -- cgit 1.4.1