From fad48ffa27af96ee0d9489ded88f80c1eeb238dc Mon Sep 17 00:00:00 2001 From: Hiltjo Posthuma Date: Mon, 14 Mar 2022 19:22:42 +0100 Subject: stricter error checking in file streams (input, output) This also makes the programs exit with a non-zero status when a read or write error occurs. This makes checking the exit status more reliable in scripts. A simple example to simulate a disk with no space left: curl -s 'https://codemadness.org/atom.xml' | sfeed > f /mnt/test: write failed, file system is full echo $? 0 Which now produces: curl -s 'https://codemadness.org/atom.xml' | sfeed > f /mnt/test: write failed, file system is full write error: echo $? 1 Tested with a small mfs on OpenBSD, fstab entry: swap /mnt/test mfs rw,nodev,nosuid,-s=1M 0 0 --- util.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'util.c') diff --git a/util.c b/util.c index db43e0c..ed0b5c9 100644 --- a/util.c +++ b/util.c @@ -46,6 +46,16 @@ errx(int exitstatus, const char *fmt, ...) exit(exitstatus); } +/* Handle read or write errors for a FILE * stream */ +void +checkfileerror(FILE *fp, const char *name, int mode) +{ + if (mode == 'r' && ferror(fp)) + errx(1, "read error: %s", name); + else if (mode == 'w' && (fflush(fp) || ferror(fp))) + errx(1, "write error: %s", name); +} + /* strcasestr() included for portability */ char * strcasestr(const char *h, const char *n) -- cgit v1.2.3