[PATCH 08/17] setterm: clean up screendump()

Sami Kerola
2014-05-18T14:06:11Z

term-utils/setterm.c | 92 +++++++++++++++++++++++++++-------------------------
1 file changed, 47 insertions(+), 45 deletions(-)

diff --git a/term-utils/setterm.c b/term-utils/setterm.c
index 05ea387..d889db4 100644
--- a/term-utils/setterm.c
+++ b/term-utils/setterm.c
@@ -144,7 +144,7 @@ enum {
#define TABS_MAX 160
#define BLENGTH_MAX 2000

-/* Option controls. */
+/* Command controls. */
struct setterm_control {
char *opt_te_terminal_name; /* terminal name */
int opt_bl_min; /* blank screen */
@@ -152,6 +152,7 @@ struct setterm_control {
int opt_bfreq_f; /* bell frequency in Hz */
int opt_sn_num; /* console number to be snapshoted */
char *opt_sn_name; /* path to write snap */
+ char *in_device; /* device to snapshot */
int opt_msglevel_num; /* printk() loging level */
int opt_ps_mode; /* powersave mode */
int opt_pd_min; /* powerdown time */
@@ -721,15 +722,18 @@ static void show_tabs(void)
}
}

-static void screendump(struct setterm_control *ctl, FILE *F)
+static void __attribute__((__noreturn__)) read_error(struct setterm_control *ctl)
+{
+ if (ctl->opt_sn_num != 0)
+ errx(EXIT_DUMPFILE, _("Couldn't read %s"), ctl->in_device);
+ else
+ errx(EXIT_DUMPFILE, _("Couldn't read neither /dev/vcsa0 nor /dev/vcsa"));
+}
+
+static int open_snapshot_device(struct setterm_control *ctl)
{
char infile[MAXPATHLEN];
- unsigned char header[4];
- unsigned int rows, cols;
int fd;
- size_t i, j;
- ssize_t rc;
- char *inbuf = NULL, *outbuf = NULL, *p, *q;

sprintf(infile, "/dev/vcsa%d", ctl->opt_sn_num);
fd = open(infile, O_RDONLY);
@@ -744,25 +748,47 @@ static void screendump(struct setterm_control *ctl, FILE *F)
sprintf(infile, "/dev/vcc/a%.0u", ctl->opt_sn_num);
fd = open(infile, O_RDONLY);
}
- if (fd < 0) {
- sprintf(infile, "/dev/vcsa%d", ctl->opt_sn_num);
- goto read_error;
- }
+ ctl->in_device = infile;
+ if (fd < 0)
+ read_error(ctl);
+ return fd;
+}
+
+static void screendump(struct setterm_control *ctl)
+{
+ unsigned char header[4];
+ unsigned int rows, cols;
+ int fd;
+ FILE *out;
+ size_t i, j;
+ ssize_t rc;
+ char *inbuf, *outbuf, *p, *q;
+ char dump_default[] = "screen.dump";
+
+ /* open source and destination files */
+ fd = open_snapshot_device(ctl);
+ if (!ctl->opt_sn_name)
+ ctl->opt_sn_name = dump_default;
+ out = fopen(ctl->opt_sn_name, ctl->opt_snap ? "w" : "a");
+ if (!out)
+ err(EXIT_DUMPFILE, _("can not open dump file %s for output"), ctl->opt_sn_name);
+ /* determine snapshot size */
if (read(fd, header, 4) != 4)
- goto read_error;
+ read_error(ctl);
rows = header[0];
cols = header[1];
if (rows * cols == 0)
- goto read_error;
-
+ read_error(ctl);
+ /* allocate buffers */
inbuf = xmalloc(rows * cols * 2);
outbuf = xmalloc(rows * (cols + 1));
-
+ /* read input */
rc = read(fd, inbuf, rows * cols * 2);
if (rc < 0 || (size_t)rc != rows * cols * 2)
- goto read_error;
+ read_error(ctl);
p = inbuf;
q = outbuf;
+ /* copy inbuf to outbuf */
for (i = 0; i < rows; i++) {
for (j = 0; j < cols; j++) {
*q++ = *p;
@@ -772,27 +798,14 @@ static void screendump(struct setterm_control *ctl, FILE *F)
q--;
*q++ = '\n';
}
- if (fwrite(outbuf, 1, q - outbuf, F) != (size_t)(q - outbuf)) {
- warnx(_("Error writing screendump"));
- goto error;
- }
+ fwrite(outbuf, 1, q - outbuf, out);
+ /* clean up allocations */
close(fd);
free(inbuf);
free(outbuf);
+ if (close_stream(out) != 0)
+ errx(EXIT_FAILURE, _("write error"));
return;
-
- read_error:
- if (ctl->opt_sn_num != 0)
- warnx(_("Couldn't read %s"), infile);
- else
- warnx(_("Couldn't read neither /dev/vcsa0 nor /dev/vcsa"));
-
- error:
- if (fd >= 0)
- close(fd);
- free(inbuf);
- free(outbuf);
- exit(EXIT_FAILURE);
}

static void perform_sequence(struct setterm_control *ctl)
@@ -1013,18 +1026,7 @@ static void perform_sequence(struct setterm_control *ctl)

/* -snap [1-NR_CONS]. */
if (ctl->opt_snap || ctl->opt_append) {
- FILE *F;
- char dump_default[] = "screen.dump";
-
- if (!ctl->opt_sn_name)
- ctl->opt_sn_name = dump_default;
- F = fopen(ctl->opt_sn_name, ctl->opt_snap ? "w" : "a");
- if (!F)
- err(EXIT_DUMPFILE, _("can not open dump file %s for output"),
- ctl->opt_sn_name);
- screendump(ctl, F);
- if (close_stream(F) != 0)
- errx(EXIT_FAILURE, _("write error"));
+ screendump(ctl);
}

/* -msg [on|off]. */
--
1.9.2