From 1d8d86aeb54c0c5439eb07a4bc1b03983fb9d6e8 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Fri, 19 Dec 2014 23:59:54 -0500 Subject: [PATCH] fix stderr locking and ferror semantics in getopt message printing if writing the error message fails, POSIX requires that ferror(stderr) be set. and as a function that operates on a stdio stream, getopt is required to lock the stream it uses, stderr. fwrite calls are used instead of fprintf since there is a demand from some users not to pull in heavy stdio machinery via getopt. this mimics the original code using write. --- src/misc/getopt.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) diff --git a/src/misc/getopt.c b/src/misc/getopt.c index e77e460a..104b5f70 100644 --- a/src/misc/getopt.c +++ b/src/misc/getopt.c @@ -11,6 +11,17 @@ int optind=1, opterr=1, optopt, __optpos, __optreset=0; #define optpos __optpos weak_alias(__optreset, optreset); +void __getopt_msg(const char *a, const char *b, const char *c, int l) +{ + FILE *f = stderr; + flockfile(f); + fwrite(a, strlen(a), 1, f) + && fwrite(b, strlen(b), 1, f) + && fwrite(c, l, 1, f) + && putc('\n', f); + funlockfile(f); +} + int getopt(int argc, char * const argv[], const char *optstring) { int i; @@ -66,24 +77,17 @@ int getopt(int argc, char * const argv[], const char *optstring) } while (l && d != c); if (d != c) { - if (optstring[0] != ':' && opterr) { - write(2, argv[0], strlen(argv[0])); - write(2, ": illegal option: ", 18); - write(2, optchar, k); - write(2, "\n", 1); - } + if (optstring[0] != ':' && opterr) + __getopt_msg(argv[0], ": illegal option: ", optchar, k); return '?'; } if (optstring[i] == ':') { if (optstring[i+1] == ':') optarg = 0; else if (optind >= argc) { if (optstring[0] == ':') return ':'; - if (opterr) { - write(2, argv[0], strlen(argv[0])); - write(2, ": option requires an argument: ", 31); - write(2, optchar, k); - write(2, "\n", 1); - } + if (opterr) __getopt_msg(argv[0], + ": option requires an argument: ", + optchar, k); return '?'; } if (optstring[i+1] != ':' || optpos) { -- 2.25.1