diff --git a/daemon.c b/daemon.c
index cb946e3c95f16d..3fdb6e83c40ec2 100644
--- a/daemon.c
+++ b/daemon.c
@@ -1308,17 +1308,21 @@ int cmd_main(int argc, const char **argv)
 			continue;
 		}
 		if (skip_prefix(arg, "--timeout=", &v)) {
-			timeout = atoi(v);
+			if (strtoul_ui(v, 10, &timeout) < 0) {
+				die("'%s': not a valid integer for --timeout", v);
+			}
 			continue;
 		}
 		if (skip_prefix(arg, "--init-timeout=", &v)) {
-			init_timeout = atoi(v);
+			if (strtoul_ui(v, 10, &init_timeout) < 0) {
+				die("'%s': not a valid integer for --init-timeout", v);
+			}
 			continue;
 		}
 		if (skip_prefix(arg, "--max-connections=", &v)) {
-			max_connections = atoi(v);
-			if (max_connections < 0)
-				max_connections = 0;	        /* unlimited */
+			if (strtol_i(v, 10, &max_connections) != 0 || max_connections < 0) {
+				max_connections = 0;  /* unlimited */
+			}
 			continue;
 		}
 		if (!strcmp(arg, "--strict-paths")) {
diff --git a/imap-send.c b/imap-send.c
index 954cc9be652980..110119c5294f6a 100644
--- a/imap-send.c
+++ b/imap-send.c
@@ -668,12 +668,12 @@ static int parse_response_code(struct imap_store *ctx, struct imap_cmd_cb *cb,
 		return RESP_BAD;
 	}
 	if (!strcmp("UIDVALIDITY", arg)) {
-		if (!(arg = next_arg(&s)) || !(ctx->uidvalidity = atoi(arg))) {
+		if (!(arg = next_arg(&s)) || strtol_i(arg, 10, &ctx->uidvalidity) != 0) {
 			fprintf(stderr, "IMAP error: malformed UIDVALIDITY status\n");
 			return RESP_BAD;
 		}
 	} else if (!strcmp("UIDNEXT", arg)) {
-		if (!(arg = next_arg(&s)) || !(imap->uidnext = atoi(arg))) {
+		if (!(arg = next_arg(&s)) || strtol_i(arg, 10, &imap->uidnext) != 0) {
 			fprintf(stderr, "IMAP error: malformed NEXTUID status\n");
 			return RESP_BAD;
 		}
@@ -686,8 +686,8 @@ static int parse_response_code(struct imap_store *ctx, struct imap_cmd_cb *cb,
 		for (; isspace((unsigned char)*p); p++);
 		fprintf(stderr, "*** IMAP ALERT *** %s\n", p);
 	} else if (cb && cb->ctx && !strcmp("APPENDUID", arg)) {
-		if (!(arg = next_arg(&s)) || !(ctx->uidvalidity = atoi(arg)) ||
-		    !(arg = next_arg(&s)) || !(*(int *)cb->ctx = atoi(arg))) {
+		if (!(arg = next_arg(&s)) || (strtol_i(arg, 10, &ctx->uidvalidity) != 0) ||
+			!(arg = next_arg(&s)) || (strtol_i(arg, 10, (int *)cb->ctx) != 0)) {
 			fprintf(stderr, "IMAP error: malformed APPENDUID status\n");
 			return RESP_BAD;
 		}
@@ -773,7 +773,10 @@ static int get_cmd_result(struct imap_store *ctx, struct imap_cmd *tcmd)
 			if (!tcmd)
 				return DRV_OK;
 		} else {
-			tag = atoi(arg);
+			if (strtol_i(arg, 10, &tag) != 0) {
+				fprintf(stderr, "IMAP error: malformed tag %s\n", arg);
+				return RESP_BAD;
+			}
 			for (pcmdp = &imap->in_progress; (cmdp = *pcmdp); pcmdp = &cmdp->next)
 				if (cmdp->tag == tag)
 					goto gottag;
diff --git a/merge-ll.c b/merge-ll.c
index 8e63071922b41c..2bfee0f2c6b0d5 100644
--- a/merge-ll.c
+++ b/merge-ll.c
@@ -427,8 +427,7 @@ enum ll_merge_result ll_merge(mmbuffer_t *result_buf,
 	git_check_attr(istate, path, check);
 	ll_driver_name = check->items[0].value;
 	if (check->items[1].value) {
-		marker_size = atoi(check->items[1].value);
-		if (marker_size <= 0)
+		if (strtol_i(check->items[1].value, 10, &marker_size) != 0 || marker_size <= 0)
 			marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
 	}
 	driver = find_ll_merge_driver(ll_driver_name);
@@ -454,8 +453,7 @@ int ll_merge_marker_size(struct index_state *istate, const char *path)
 		check = attr_check_initl("conflict-marker-size", NULL);
 	git_check_attr(istate, path, check);
 	if (check->items[0].value) {
-		marker_size = atoi(check->items[0].value);
-		if (marker_size <= 0)
+		if (strtol_i(check->items[0].value, 10, &marker_size) != 0 || marker_size <= 0)
 			marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
 	}
 	return marker_size;
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 4896a801ee28d2..12855178ffbd35 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -281,8 +281,9 @@ test_expect_success 'stop on conflicting pick' '
 	test_cmp expect2 file1 &&
 	test "$(git diff --name-status |
 		sed -n -e "/^U/s/^U[^a-z]*//p")" = file1 &&
-	test 4 = $(grep -v "^#" < .git/rebase-merge/done | wc -l) &&
-	test 0 = $(grep -c "^[^#]" < .git/rebase-merge/git-rebase-todo)
+	grep -v "^#" <.git/rebase-merge/done >actual &&
+	test_line_count = 4 actual &&
+	test 0 = $(grep -c "^[^#]" <.git/rebase-merge/git-rebase-todo)
 '
 
 test_expect_success 'show conflicted patch' '
@@ -319,7 +320,8 @@ test_expect_success 'retain authorship' '
 	GIT_AUTHOR_NAME="Twerp Snog" git commit -m "different author" &&
 	git tag twerp &&
 	git rebase -i --onto primary HEAD^ &&
-	git show HEAD | grep "^Author: Twerp Snog"
+	git show HEAD >actual &&
+	grep "^Author: Twerp Snog" actual
 '
 
 test_expect_success 'retain authorship w/ conflicts' '
@@ -360,7 +362,8 @@ test_expect_success 'squash' '
 '
 
 test_expect_success 'retain authorship when squashing' '
-	git show HEAD | grep "^Author: Twerp Snog"
+	git show HEAD >actual &&
+	grep "^Author: Twerp Snog" actual
 '
 
 test_expect_success '--continue tries to commit' '
@@ -374,7 +377,8 @@ test_expect_success '--continue tries to commit' '
 		FAKE_COMMIT_MESSAGE="chouette!" git rebase --continue
 	) &&
 	test_cmp_rev HEAD^ new-branch1 &&
-	git show HEAD | grep chouette
+	git show HEAD >actual &&
+	grep chouette actual
 '
 
 test_expect_success 'verbose flag is heeded, even after --continue' '
@@ -397,7 +401,9 @@ test_expect_success 'multi-squash only fires up editor once' '
 			git rebase -i $base
 	) &&
 	test $base = $(git rev-parse HEAD^) &&
-	test 1 = $(git show | grep ONCE | wc -l)
+	git show >output &&
+	grep ONCE output >actual &&
+	test_line_count = 1 actual
 '
 
 test_expect_success 'multi-fixup does not fire up editor' '
@@ -410,7 +416,8 @@ test_expect_success 'multi-fixup does not fire up editor' '
 			git rebase -i $base
 	) &&
 	test $base = $(git rev-parse HEAD^) &&
-	test 0 = $(git show | grep NEVER | wc -l) &&
+	git show >output &&
+	! grep NEVER output &&
 	git checkout @{-1} &&
 	git branch -D multi-fixup
 '
@@ -428,7 +435,9 @@ test_expect_success 'commit message used after conflict' '
 			git rebase --continue
 	) &&
 	test $base = $(git rev-parse HEAD^) &&
-	test 1 = $(git show | grep ONCE | wc -l) &&
+	git show >output &&
+	grep ONCE output >actual &&
+	test_line_count = 1 actual &&
 	git checkout @{-1} &&
 	git branch -D conflict-fixup
 '
@@ -446,7 +455,9 @@ test_expect_success 'commit message retained after conflict' '
 			git rebase --continue
 	) &&
 	test $base = $(git rev-parse HEAD^) &&
-	test 2 = $(git show | grep TWICE | wc -l) &&
+	git show >output &&
+	grep TWICE output >actual &&
+	test_line_count = 2 actual &&
 	git checkout @{-1} &&
 	git branch -D conflict-squash
 '
@@ -470,10 +481,10 @@ test_expect_success 'squash and fixup generate correct log messages' '
 	) &&
 	git cat-file commit HEAD | sed -e 1,/^\$/d > actual-squash-fixup &&
 	test_cmp expect-squash-fixup actual-squash-fixup &&
-	git cat-file commit HEAD@{2} |
-		grep "^# This is a combination of 3 commits\."  &&
-	git cat-file commit HEAD@{3} |
-		grep "^# This is a combination of 2 commits\."  &&
+	git cat-file commit HEAD@{2} >actual &&
+	grep "^# This is a combination of 3 commits\." actual &&
+	git cat-file commit HEAD@{3} >actual &&
+	grep "^# This is a combination of 2 commits\." actual  &&
 	git checkout @{-1} &&
 	git branch -D squash-fixup
 '
@@ -489,7 +500,9 @@ test_expect_success 'squash ignores comments' '
 			git rebase -i $base
 	) &&
 	test $base = $(git rev-parse HEAD^) &&
-	test 1 = $(git show | grep ONCE | wc -l) &&
+	git show >output &&
+	grep ONCE output >actual &&
+	test_line_count = 1 actual &&
 	git checkout @{-1} &&
 	git branch -D skip-comments
 '
@@ -505,7 +518,9 @@ test_expect_success 'squash ignores blank lines' '
 			git rebase -i $base
 	) &&
 	test $base = $(git rev-parse HEAD^) &&
-	test 1 = $(git show | grep ONCE | wc -l) &&
+	git show >output &&
+	grep ONCE output >actual &&
+	test_line_count = 1 actual &&
 	git checkout @{-1} &&
 	git branch -D skip-blank-lines
 '
@@ -572,7 +587,8 @@ test_expect_success '--continue tries to commit, even for "edit"' '
 		FAKE_COMMIT_MESSAGE="chouette!" git rebase --continue
 	) &&
 	test edited = $(git show HEAD:file7) &&
-	git show HEAD | grep chouette &&
+	git show HEAD >actual &&
+	grep chouette actual &&
 	test $parent = $(git rev-parse HEAD^)
 '
 
@@ -757,19 +773,23 @@ test_expect_success 'reword' '
 		set_fake_editor &&
 		FAKE_LINES="1 2 3 reword 4" FAKE_COMMIT_MESSAGE="E changed" \
 			git rebase -i A &&
-		git show HEAD | grep "E changed" &&
+		git show HEAD >actual &&
+		grep "E changed" actual &&
 		test $(git rev-parse primary) != $(git rev-parse HEAD) &&
 		test_cmp_rev primary^ HEAD^ &&
 		FAKE_LINES="1 2 reword 3 4" FAKE_COMMIT_MESSAGE="D changed" \
 			git rebase -i A &&
-		git show HEAD^ | grep "D changed" &&
+		git show HEAD^ >actual &&
+		grep "D changed" actual &&
 		FAKE_LINES="reword 1 2 3 4" FAKE_COMMIT_MESSAGE="B changed" \
 			git rebase -i A &&
-		git show HEAD~3 | grep "B changed" &&
+		git show HEAD~3 >actual &&
+		grep "B changed" actual &&
 		FAKE_LINES="1 r 2 pick 3 p 4" FAKE_COMMIT_MESSAGE="C changed" \
 			git rebase -i A
 	) &&
-	git show HEAD~2 | grep "C changed"
+	git show HEAD~2 >actual &&
+	grep "C changed" actual
 '
 
 test_expect_success 'no uncommitted changes when rewording and the todo list is reloaded' '
@@ -1003,8 +1023,10 @@ test_expect_success 'rebase -i --root retain root commit author and message' '
 		set_fake_editor &&
 		FAKE_LINES="2" git rebase -i --root
 	) &&
-	git cat-file commit HEAD | grep -q "^author Twerp Snog" &&
-	git cat-file commit HEAD | grep -q "^different author$"
+	git cat-file commit HEAD >output &&
+	grep -q "^author Twerp Snog" output &&
+	git cat-file commit HEAD >actual &&
+	grep -q "^different author$" actual
 '
 
 test_expect_success 'rebase -i --root temporary sentinel commit' '
@@ -1013,7 +1035,8 @@ test_expect_success 'rebase -i --root temporary sentinel commit' '
 		set_fake_editor &&
 		test_must_fail env FAKE_LINES="2" git rebase -i --root
 	) &&
-	git cat-file commit HEAD | grep "^tree $EMPTY_TREE" &&
+	git cat-file commit HEAD >actual &&
+	grep "^tree $EMPTY_TREE" actual &&
 	git rebase --abort
 '
 
@@ -1036,7 +1059,8 @@ test_expect_success 'rebase -i --root reword original root commit' '
 		FAKE_LINES="reword 1 2" FAKE_COMMIT_MESSAGE="A changed" \
 			git rebase -i --root
 	) &&
-	git show HEAD^ | grep "A changed" &&
+	git show HEAD^ >actual &&
+	grep "A changed" actual &&
 	test -z "$(git show -s --format=%p HEAD^)"
 '
 
@@ -1048,7 +1072,8 @@ test_expect_success 'rebase -i --root reword new root commit' '
 		FAKE_LINES="reword 3 1" FAKE_COMMIT_MESSAGE="C changed" \
 		git rebase -i --root
 	) &&
-	git show HEAD^ | grep "C changed" &&
+	git show HEAD^ >actual &&
+	grep "C changed" actual &&
 	test -z "$(git show -s --format=%p HEAD^)"
 '