From ea598e719d557a876a52d0cbecb21c1fb8ff917f Mon Sep 17 00:00:00 2001 From: Jack Jamison Date: Tue, 21 Jul 2026 09:17:56 -0400 Subject: add a bunch of util and clean up --- snag/main.c | 7 +--- snag/pkg_db.c | 100 ++++++++++++++++++++++++++-------------------------------- snag/util.c | 55 ++++++++++++++++++++++++++++---- snag/util.h | 18 ++++++++--- 4 files changed, 108 insertions(+), 72 deletions(-) diff --git a/snag/main.c b/snag/main.c index eff1f2f..9804f99 100644 --- a/snag/main.c +++ b/snag/main.c @@ -1,16 +1,11 @@ #include #include "pkg_db.h" -#include "util.h" void subcmd_install(char* pkgs[], size_t count); int main(int argc, char* argv[]) { - char buf[4096]; - vstrcat(buf, "this ", "is", " a", " te", "st"); - fprintf(stderr, "buf: %s\n", buf); - // run install subcommand with each argument as a package subcmd_install(argv+1, argc-1); @@ -28,7 +23,7 @@ void subcmd_install(char* pkgs[], size_t count) { // load package description package_info_t info; if (load_package_info(&info, pkgid)) { - printf("Installing '%s'\n", info.attrs.id); + printf("Installing %s - %s\n", info.attrs.name, info.attrs.desc); } } } diff --git a/snag/pkg_db.c b/snag/pkg_db.c index ee11288..ad9eff3 100644 --- a/snag/pkg_db.c +++ b/snag/pkg_db.c @@ -1,9 +1,11 @@ #include "pkg_db.h" +#include "util.h" #include #include #include #include +#include #include #define PKG_DB "../packages" @@ -11,86 +13,72 @@ #define PKG_INFO_CMD "./get_pkg_attrs.sh" bool load_package_info(package_info_t* info, char* pkgid) { + memset(info, 0, sizeof(*info)); + size_t pkgid_len = strlen(pkgid); // construct package description directory path and ensure it exists - size_t pkgid_len = strlen(pkgid); - size_t pkg_dir_len = PKG_DB_LEN + pkgid_len + 1; - char* pkg_dir = malloc(pkg_dir_len + 1); - if (!pkg_dir) { - fprintf(stderr, "Failed to alloc pkg_dir\n"); - exit(1); - } // pkg_dir = "PKG_DB/pkgid" - memcpy(pkg_dir, PKG_DB, PKG_DB_LEN); - pkg_dir[PKG_DB_LEN] = '/'; - memcpy(&pkg_dir[PKG_DB_LEN + 1], pkgid, pkgid_len + 1); - - if (access(pkg_dir, F_OK) != 0) { - fprintf(stderr, "Package '%s' not found\n", pkgid); - free(pkg_dir); - return false; - } + size_t pkg_dir_len = PKG_DB_LEN + pkgid_len + 1; + char* pkg_dir = emalloc(pkg_dir_len + 1, "pkg_dir"); + { + memcpy(pkg_dir, PKG_DB, PKG_DB_LEN); + pkg_dir[PKG_DB_LEN] = '/'; + memcpy(pkg_dir + PKG_DB_LEN + 1, pkgid, pkgid_len); + pkg_dir[pkg_dir_len] = '\0'; + if (access(pkg_dir, F_OK) != 0) { + eprintf("Package '%s' not found\n", pkgid); + free(pkg_dir); + return false; + } + } // construct package description script path and ensure it exists + // script_path = "pkg_dir/pkgid.sh" size_t script_path_len = pkg_dir_len + pkgid_len + 4; - info->script_path = malloc(script_path_len + 1); - if (!info->script_path) { - fprintf(stderr, "Failed to alloc info->script_path\n"); - exit(1); - } - - memcpy(info->script_path, pkg_dir, pkg_dir_len); - info->script_path[pkg_dir_len] = '/'; - memcpy(&info->script_path[pkg_dir_len + 1], pkgid, pkgid_len); - memcpy(&info->script_path[script_path_len - 3], ".sh", 4); - free(pkg_dir); - if (access(info->script_path, F_OK) != 0) { - fprintf(stderr, "Package '%s' broken, doesn't have description script\n", pkgid); - free(info->script_path); - return false; - } + info->script_path = emalloc(script_path_len + 1, "info->script_path"); + { + memcpy(info->script_path, pkg_dir, pkg_dir_len); + info->script_path[pkg_dir_len] = '/'; + memcpy(&info->script_path[pkg_dir_len + 1], pkgid, pkgid_len); + memcpy(&info->script_path[script_path_len - 3], ".sh", 4); + free(pkg_dir); + if (access(info->script_path, F_OK) != 0) { + eprintf("Package '%s' broken, doesn't have description script\n", pkgid); + free(info->script_path); + return false; + } + } + // PIPE and FORK to run get pkg attrs script int pipefds[2] = {0}; - if (pipe(pipefds) < 0) { - fprintf(stderr, "Failed to create pipe\n"); - exit(1); - } + if (pipe(pipefds) < 0) error_out("failed to pipe: %s", strerror(errno)); pid_t pid = fork(); - if (pid < 0) { - fprintf(stderr, "Failed to create child process\n"); - exit(1); - } + if (pid < 0) error_out("failed to fork: %s", strerror(errno)); + // child proc if (pid == 0) { + // write my stdout the the pipe close(pipefds[0]); dup2(pipefds[1], STDOUT_FILENO); close(pipefds[1]); - + // exec into get attr script char* argv[] = { PKG_INFO_CMD, info->script_path, NULL }; char* envp[] = { NULL }; execve(PKG_INFO_CMD, argv, envp); - fprintf(stderr, "execve failed\n"); - exit(127); + error_out("execve failed"); } + // wait for child to finish int wstatus; - if (waitpid(pid, &wstatus, 0) < 0) { - fprintf(stderr, "waitpid failed\n"); - exit(1); - } - if (WEXITSTATUS(wstatus) == 127) { - exit(1); - } + if (waitpid(pid, &wstatus, 0) < 0) error_out("waitpid failed: %s", strerror(errno)); + if (WEXITSTATUS(wstatus) != 0) error_out("failed to execute get pkg attr script"); + // read all bytes from pipe ssize_t bytes_read = read(pipefds[0], info->package_attrs, sizeof(info->package_attrs)); - if (bytes_read < 0) { - fprintf(stderr, "Failed to read from pipe\n"); - exit(1); - } - - free(info->script_path); + if (bytes_read < 0) error_out("Failed to read from pipe"); + // read attributes from pipe data for (int i = 0; i < bytes_read;) { char atype = info->package_attrs[i]; i++; diff --git a/snag/util.c b/snag/util.c index c4137f6..d8947a7 100644 --- a/snag/util.c +++ b/snag/util.c @@ -1,15 +1,58 @@ -#include +#include #include +#include + +#include "util.h" + +void eprintf(const char *format, ...) { + // send that shi to stderr + va_list args; + va_start(args, format); + vfprintf(stderr, format, args); + va_end(args); +} + +void error_out(const char *format, ...) { + va_list args; + va_start(args, format); + vfprintf(stderr, format, args); + va_end(args); + fprintf(stderr, "\n"); + exit(1); +} + +void* emalloc(size_t size, char* alloc_reason) { + void* d = malloc(size); + if (d == NULL) error_out("Failed to allocate %s", alloc_reason); + return d; +} + +char* vastrcat_(int dummy, ...) { -void vstrcat_(char* dest, ...) { va_list args; - va_start(args, dest); + va_list args2; + va_start(args, dummy); + va_copy(args2, args); + + // get len of output string + size_t len = 0; while (1) { char* arg = va_arg(args, char*); if (!arg) break; - memcpy(dest, arg, strlen(arg)); - dest += strlen(arg); + len += strlen(arg); } va_end(args); - *dest = 0; + + // allocate and build output + char* output = malloc(len + 1); + char* p = output; + while (1) { + char* arg = va_arg(args2, char*); + if (!arg) break; + memcpy(p, arg, strlen(arg)); + p += strlen(arg); + } + va_end(args2); + + return output; } diff --git a/snag/util.h b/snag/util.h index 88906cc..6f23607 100644 --- a/snag/util.h +++ b/snag/util.h @@ -1,6 +1,16 @@ #ifndef UTIL_H #define UTIL_H -#include -#define vstrcat(dest, ...) vstrcat_(dest, __VA_ARGS__, NULL) -void vstrcat_(char* dest, ...); -#endif // UTIL_H + +#include +#include + +// utility for errors +void eprintf(const char *format, ...) __attribute__((format(printf, 1, 2))); +void error_out(const char *format, ...) __attribute__((format(printf, 1, 2))); // panic, as the kids say +void* emalloc(size_t size, char* alloc_reason); + +// string functions +char* vastrcat_(int dummy, ...); +#define vastrcat(...) vastrcat_(0, __VA_ARGS__, NULL) + +#endif -- cgit v1.2.3