diff options
Diffstat (limited to 'spm.c')
| -rw-r--r-- | spm.c | 352 |
1 files changed, 352 insertions, 0 deletions
@@ -0,0 +1,352 @@ +/** + * SPM - Simple Package Manager + * @file spm.c + */ + +#include <ctype.h> +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <limits.h> +#include <stdarg.h> +#include <string.h> +#include <unistd.h> +#include <glob.h> + +#define SYSERROR stderr, "%s:%s:%d: %s\n", __FILE__, __FUNCTION__, __LINE__, strerror(errno) +#define DIRSEP_WIN32 '\\' +#define DIRSEP_UNIX '/' +#if defined(_WIN32) +#define DIRSEP DIRSEP_WIN32 +#define NOT_DIRSEP DIRSEP_UNIX +#else +#define DIRSEP DIRSEP_UNIX +#define NOT_DIRSEP DIRSEP_WIN32 +#endif + +#define PKG_DIR "../pkgs" + +/** + * A wrapper for `popen()` that executes non-interactive programs and reports their exit value. + * To redirect stdout and stderr you must do so from within the `fmt` string + * + * ~~~{.c} + * int fd = 1; // stdout + * const char *log_file = "log.txt"; + * char *buf; + * int status; + * + * // Send stderr to stdout + * status = shell(buf, "foo 2>&1"); + * // Send stdout and stderr to /dev/null + * status = shell(buf, "bar &>/dev/null"); + * // Send stdout from baz to log.txt + * status = shell(buf, "baz %d>%s", fd, log_file); + * // Do not record or redirect output from any streams + * status = shell(NULL, "biff"); + * ~~~ + * + * @param buf buffer to hold program output (to ignore output, set to NULL) + * @param options change behavior of the function + * @param fmt shell command to execute (accepts `printf` style formatters) + * @param ... variadic arguments (used by `fmt`) + * @return shell exit code + */ +#define SHELL_DEFAULT 1 << 0 +#define SHELL_OUTPUT 1 << 1 +int shell(char **buf, u_int8_t option, const char *fmt, ...) { + va_list args; + va_start(args, fmt); + + FILE *proc; + int status = -1; + char *outbuf = (char *)calloc(1, sizeof(char)); + if (!outbuf) { + fprintf(SYSERROR); + exit(errno); + } + char *cmd = (char *)calloc(PATH_MAX, sizeof(char)); + if (!cmd) { + fprintf(SYSERROR); + exit(errno); + } + + vsnprintf(cmd, PATH_MAX, fmt, args); + + proc = popen(cmd, "r"); + if (!proc) { + return status; + } + + size_t bytes_read = 0; + size_t i = 0; + size_t new_buf_size = 0; + if (option & SHELL_OUTPUT) { + *buf = (char *)calloc(BUFSIZ, sizeof(char)); + + while (!feof(proc)) { + *outbuf = fgetc(proc); + + if (i >= BUFSIZ) { + new_buf_size = BUFSIZ + (i + bytes_read); + (*buf) = (char *)realloc((*buf), new_buf_size); + i = 0; + } + if (isascii(*outbuf)) { + (*buf)[bytes_read] = *outbuf; + } + bytes_read++; + i++; + } + } + status = pclose(proc); + va_end(args); + free(outbuf); + free(cmd); + return status; +}; + +/* +int tar_extract_file(const char *archive, const char* filename, const char *destination) { + int status = -1; + char cmd[PATH_MAX]; + char output[3]; + sprintf(cmd, "tar xf %s %s -C %s 2>&1", archive, filename, destination); + FILE *proc = popen(cmd, "r"); + if (!proc) { + return status; + } + while (!feof(proc)) { + fgets(output, 2, proc); + printf("%s", output); + } + putchar('\n'); + return pclose(proc); +}; + */ + +/** + * glob callback function + * @param epath path to file that generated the error condition + * @param eerrno the error condition + * @return the error condition + */ +int errglob(const char *epath, int eerrno) { + fprintf(stderr, "glob matching error: %s (%d)", epath, eerrno); + return eerrno; +} + +/** + * Determine how many times the character `ch` appears in `sptr` string + * @param sptr string to scan + * @param ch character to find + * @return count of characters found + */ +int num_chars(const char *sptr, int ch) { + int result = 0; + for (int i = 0; sptr[i] != '\0'; i++) { + if (sptr[i] == ch) { + result++; + } + } + return result; +} + +/** + * Scan for `pattern` string at the beginning of `sptr` + * + * @param sptr string to scan + * @param pattern string to search for + * @return 0 = success, -1 = failure + */ +int startswith(const char *sptr, const char *pattern) { + for (int i = 0; i < strlen(pattern); i++) { + if (sptr[i] != pattern[i]) { + return -1; + } + } + return 0; +} + +/** + * Scan for `pattern` string at the end of `sptr` + * + * @param sptr string to scan + * @param pattern string to search for + * @return 0 = success, -1 = failure + */ +int endswith(const char *sptr, const char *pattern) { + size_t sptr_size = strlen(sptr); + size_t pattern_size = strlen(pattern); + for (size_t s = sptr_size - pattern_size, p = 0 ; s < sptr_size; s++, p++) { + if (sptr[s] != pattern[p]) { + return -1; + } + } + return 0; +} + +/** + * Converts Win32 path to Unix path, and vice versa + * - On UNIX, Win32 paths will be converted UNIX + * - On Win32, UNIX paths will be converted to Win32 + * + * This function is platform dependent. + * + * @param path a system path + * @return string (caller is responsible for `free`ing memory) + */ +char *normpath(const char *path) { + char *result = strdup(path); + char *tmp = result; + + while (*tmp) { + if (*tmp == NOT_DIRSEP) { + *tmp = DIRSEP; + tmp++; + continue; + } + tmp++; + } + return result; +} + +/** + * This function scans `sptr` from right to left removing any matches to `suffix` + * from the string. + * + * @param sptr string to be modified + * @param suffix string to be removed from `sptr` + */ +void strip(char *sptr, const char *suffix) { + if (!sptr || !suffix) { + return; + } + size_t sptr_len = strlen(sptr); + size_t suffix_len = strlen(suffix); + intptr_t target_offset = sptr_len - suffix_len; + + // Prevent access to memory below input string + if (target_offset < 0) { + return; + } + + // Create a pointer to + char *target = sptr + target_offset; + if (!strcmp(target, suffix)) { + // Purge the suffix + memset(target, '\0', suffix_len); + // Recursive call continues removing suffix until it is gone + strip(sptr, suffix); + } +} + +/** + * Deletes any characters matching `chars` from `sptr` string + * + * @param sptr string to be modified in-place + * @param chars a string containing characters (e.g. " \n" would delete whitespace and line feeds) + */ +void strchrdel(char *sptr, const char *chars) { + while (*sptr != '\0') { + for (int i = 0; chars[i] != '\0'; i++) { + if (*sptr == chars[i]) { + memmove(sptr, sptr + 1, strlen(sptr)); + } + } + sptr++; + } +} + +char *find_file(const char *root, const char *filename) { + glob_t results; + int glob_flags = 0; + int match = 0; + char *rootpath = NULL; + char *path = NULL; + + // GUARD + if (!root || !filename || strstr(filename, "..") || strstr(filename, "./")) { + return NULL; + } + + if (!(path = (char *)calloc(PATH_MAX + 1, sizeof(char)))) { + fprintf(SYSERROR); + exit(errno); + } + + if (!(rootpath = realpath(root, NULL))) { + return NULL; + } + + strcat(path, rootpath); + strcat(path, "/"); + strcat(path, filename); + + // Save a little time if the file exists + if (access(path, F_OK) != -1) { + return path; + } + + // Inject wildcard + strcat(path, "*"); + // Search for the file + match = glob(path, glob_flags, errglob, &results); + + if (match != 0) { + // report critical errors except GLOB_NOMATCH + if (match == GLOB_NOSPACE || match == GLOB_ABORTED) { + fprintf(SYSERROR); + } + return NULL; + } + + // Resize path to the length of the first match + char *want = results.gl_pathv[0]; + if (!(path = (char *)realloc(path, strlen(want) + 1))) { + fprintf(SYSERROR); + exit(errno); + } + + // Replace path string with wanted path string + strncpy(path, want, strlen(want)); + + free(rootpath); + globfree(&results); + return path; +} + +char *find_package(const char *filename) { + return find_file(PKG_DIR, filename); +} + +int main() { + const char *pkg_name = "python"; + char *package = NULL; + package = find_package(pkg_name); + if (package != NULL) { + printf("Package found: %s\n", package); + free(package); + } + else { + fprintf(stderr,"Package does not exist: %s\n", pkg_name); + } + + const char *testpath = "x:\\a\\b\\c"; + const char *teststring = "this is test!"; + char *normalized = normpath(testpath); + char *buf = NULL; + + printf("%s becomes %s\n", testpath, normalized); + printf("%d\n", startswith(testpath, "x:\\")); + printf("%d\n", endswith(teststring, "test!")); + //tar_extract_file("one", "two", testpath); + + int retval = -1; + retval = shell(&buf, SHELL_OUTPUT, "env; env; env; env; env; env; env; env"); + strip(buf, "\n"); + printf("%s\n", buf); + + free(normalized); + return 0; +}
\ No newline at end of file |